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Hot Springs for Insomnia | General Indication Across All 10 Spring Types

Published May 6, 2026·1min read

Insomnia is listed as a general bathing indication for all 10 Japanese spring types. Simple springs carry an additional specific indication for insomnia, making them the gentlest choice for sensitive bathers. The key mechanism is the "core temperature rhythm": bathing temporarily raises deep body temperature, and the subsequent drop 1–2 hours later triggers natural sleep onset.

Hot Springs for Insomnia | General Indication Across All 10 Spring Types
Applicable spring types
10 types
Analysis records
368 records
Table of Contents
  1. Spring types indicated for insomnia
  2. How onsen bathing promotes sleep
  3. Bathing technique for insomnia

Spring types indicated for insomnia

Insomnia is a general bathing indication shared by all 10 spring types, and the thermal effect of any onsen is thought to support sleep. Simple springs — lowest in irritation and the only type with a specific indication for insomnia — are the first choice, followed by the deeply relaxing bicarbonate springs and the heat-retaining chloride springs.

insomnia listed as a specific bathing indication — lowest irritation, suitable for everyone

a soft feel that many find relaxing before sleep

strong heat retention is said to prevent post-bath chill

a calming, recuperative spring that settles mind and body

See the full 10-spring-type guide

How onsen bathing promotes sleep

The core body temperature rhythm is the key: a warm bath temporarily raises deep body temperature; the subsequent fall 1–2 hours later is thought to ease sleep onset. This applies to every spring type through the thermal effect.

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Bathing technique for insomnia

  1. Keep water temperature at 38–40°C — above 41°C activates the sympathetic system and can delay sleepA lukewarm bath in this temperature range encourages relaxation by engaging the parasympathetic nervous system. Water hotter than 41°C can have the opposite effect, stimulating the sympathetic nervous system and promoting wakefulness, which may interfere with sleep.
  2. Soak for 15–20 minutesThis duration is ideal for gradually raising your deep body temperature without causing stress to your system. It provides enough time for the warmth of the water to take hold, preparing your body for the cooling phase that is said to bring on sleepiness.
  3. Bathe 1–2 hours before bedtime to synchronise body temperature drop with sleep onsetThis timing is key to leveraging your body's natural sleep mechanism. After your bath, your deep body temperature will begin to fall, and this cooling process signals to your brain that it is time to sleep. Aligning this drop with your bedtime helps induce natural drowsiness.
  4. After bathing, dim lights and avoid screens to preserve parasympathetic nervous system activityAfter a relaxing bath, your body is in a parasympathetic state, which is ideal for sleep. Exposure to bright lights or blue light from screens can disrupt this state by stimulating the brain, making it harder to fall asleep. A calm, dim environment helps maintain relaxation.

Related Onsen Facilities

40 matches
Hakoneyumotoonsen Hakonesuimeisou Simple Spring
Simple SpringInfo pending
Hakoneyumotoonsen Hakonesuimeisou
水明荘
Kanagawa Hakone· 箱根湯本温泉(水明荘)Hakone Onsen
Gentle Gateway Spring

Hakone-Yumoto is said to date back to the Nara period, the oldest of Hakone's seven historic spas. In the Edo period it thrived as a healing stop for travelers on the Tokaido, nestled by the forest of Sounji Temple, linked to the Hojo clan. This source rises at 45.2°C as an alkaline simple spring of pH 8.5, its softly balanced water wrapping the skin in smoothness. Gentle enough for all ages, it is a spring that unwinds city fatigue at the gateway to Hakone.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.5
0714
TEMP45.2℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer that leaves a hydrated feel on the skin.

A trace component with gentle antibacterial and anti-inflammatory action.

69.1 mg/kg

Softens dead skin cells for a silky bathing feel.

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Okamoto-ya Ryokan Acidic Spring
Acidic SpringSulphur SpringSimple SpringInfo pending
Okamoto-ya Ryokan
岡本屋旅館
Oita Beppu· 岡本屋旅館
Milky Blue Waters of Myoban

Myoban Onsen prospered in the Edo period through alum production and still keeps rows of thatched huts where yunohana sulfur flowers are made. Here the Okamotoya Ryokan source gushes naturally at 74.4°C in Myoban 3-kumi; colorless as it emerges, it turns a milky, bluish white once it meets the air in the bath. Its acidity gently loosens old skin cells, leaving a soft, light feeling afterward, and it suits anyone who wishes to steep in dense sulfur water amid mountain steam.

Onsen RyokanPrivate Rental BathTattoo OK (public bath)
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2.6
0714
TEMP74.4℃
0℃50℃100℃
KEY MINERALS

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

4.3 mg/kg

Tightens the skin and balances sebum.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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Suimei-kan Simple Spring
Simple SpringInfo pending
Suimei-kan
水明館
Gifu 下呂市· 下呂温泉(幸田ポンプ所)Gero Onsen
Silky Waters of the Heron

Gero Onsen counts among Japan's three famous springs, and legend holds that when its waters once vanished, a white heron alighted on the Masuda riverbank to reveal a new gush sent by the healing Buddha Yakushi. The Gero Onsen Koda pump station source gathers several centrally managed wells and sends them to inns across the Koda district. Its pH 9.4 alkaline water glides softly over the skin and lingers as a light, refreshed feeling afterward, soothing travelers who seek gentle rest.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Alkaline9.4
0714
TEMP56℃
0℃50℃100℃
KEY MINERALS
17.0 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

A natural moisturizer that leaves a hydrated feel on the skin.

Gentle antibacterial action that conditions the skin.

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Matsumoto Jūjō Simple Spring
Simple SpringInfo pending
Matsumoto Jūjō
松本十帖
Nagano Matsumoto· 浅間温泉 第2号源泉Asama Onsen
Castle Town Retreat Spring

Asama Onsen is an ancient spa long loved as the back parlor of Matsumoto's castle town, said to be the "Tsukama no Yu" mentioned in the Nihon Shoki or a spring found by the Inukai clan in the Heian era. In the Edo period the Matsumoto domain kept a lord's bathhouse here, and samurai bathed in separate pools by rank. The No. 2 Source is the main spring supplying the town's inns, pumped up at around 49°C. Its alkaline water, carrying sodium, calcium and sulfate, suits travelers who want a quiet, warming soak steeped in castle-town history.

Onsen RyokanRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.8
0714
TEMP49.4℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer that leaves a hydrated feel on the skin.

1.4 mg/kg

A trace antibacterial component that keeps skin clean.

194 mg/kg

Soothes the skin and gently improves circulation.

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Akarinoyado Tougetsu Simple Spring
Simple SpringVerified
Akarinoyado Tougetsu
灯りの宿 燈月
Oita Beppu· 灯りの宿 燈月Kannawa Onsen
The Lantern Light Spring of Serenity

Gushing in the Kannawa Onsen area, one of the eight springs of Beppu, Japan's top onsen destination, the Akari no Yado Tougetsu Gensen is a relatively new source, drilled and pump-lifted for a facility that opened in 2019. It offers modern relaxation while inheriting the traditions of Kannawa, long-famed as a therapeutic spa area. With a neutral pH of 6.8, close to human skin, the water is gentle and suitable for everyone. Immersing yourself in these waters helps you forget the hustle and bustle of daily life, deeply relaxing both mind and body.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.9
0714
TEMP68.8℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

59.9 mg/kg

Softens dead skin cells for a silky bathing feel.

97.2 mg/kg

Soothes the skin and gently improves circulation.

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Atsusawabe Uzura Onsen Shiki no Yado Simple Spring
Simple SpringInfo pending
Atsusawabe Uzura Onsen Shiki no Yado
厚沢部うずら温泉 四季の宿
Hokkaido Atsusawabe Town· うずら温泉
Smooth Farmland Spring

Uzura Onsen is drawn by pump at 160 liters per minute from a well in the farmland of Uzura-cho, Atsusawabe. A 1994 analysis by the Hokkaido Institute of Public Health classified the source as an alkaline simple spring at 30.0°C and pH 8.5. Clear, odorless and tasteless, it carries sodium, chloride, bicarbonate and 122.7 mg/kg of metasilicic acid, soothing the skin with a quiet, unassuming character that suits this modest farming town in southern Hokkaido.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.5
0714
TEMP30℃
0℃50℃100℃
KEY MINERALS
18.6 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

Softens dead skin cells for a silky bathing feel.

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Kurobekyoukokutorokkodenshaekimae Firuunazuki Simple Spring
Simple SpringInfo pending
Kurobekyoukokutorokkodenshaekimae Firuunazuki
黒部峡谷トロッコ電車駅前 フィール宇奈月
Toyama Kurobe· 宇奈月温泉Unazuki Onsen
Pristine Piped Gorge Spring

This hot spring embodies the enduring passion of pioneers, delivered from Kuronagi Onsen in the upper reaches of the Kurobe River to Unazuki Onsen, approximately 7km downstream, after arduous wooden pipe laying construction in Taisho 12 (1923). Gushing at an abundant rate of approximately 2,000 liters per minute, its colorless and transparent waters seem to embody the pristine clarity of the gorge itself. With a soft touch that gently envelops the skin, it slowly warms the body to its core. Ideal for those seeking to unwind their mind and body, embraced by nature, at the various inns and public bathhouses throughout the town.

Onsen RyokanDay-use BathPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.2
0714
TEMP98.3℃
0℃50℃100℃
KEY MINERALS
6.2 mg/kg

A trace antibacterial component that keeps skin clean.

A trace component with gentle antibacterial and anti-inflammatory action.

A natural moisturizer that leaves a hydrated feel on the skin.

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Hakonekowakiemmikawayaryokan Simple Spring
Simple SpringVerified
Hakonekowakiemmikawayaryokan
箱根小涌園 三河屋旅館
Kanagawa Hakone· 小涌谷温泉 温泉村第59-3号、温泉村 第100号 混合泉Hakone Onsen
A Heritage Spring of Meiji Memory

Once a desolate area called "Lesser Hell," this land was renamed Kowakidani following a visit by Emperor Meiji, sparking its development as a hot spring resort. This combined source is one of several springs utilized in this historic onsen town. Developed by entrepreneurs in the Meiji era, the area saw the construction of numerous inns and villas. This very source has supplied water to accommodations throughout the Kowakidani area, laying the foundation for Hakone's modern onsen culture.

Onsen RyokanPrivate Rental BathRoom with Open-air BathTattoo OK (public bath)
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.4
0714
TEMP74℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

A trace component with gentle antibacterial and anti-inflammatory action.

Softens dead skin cells for a silky bathing feel.

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Namari Onsen Fuji San Ryokan Simple Spring
Simple SpringInfo pending
Namari Onsen Fuji San Ryokan
鉛温泉 藤三旅館
Iwate Hanamaki· 鉛温泉 桂の湯+下の湯(混合泉)Hanamaki Minami Onsenkyo
The Gentle Waters of the White Monkey Legend on the Toyosawa River

Namari Onsen, said to have opened some 600 years ago, is the single-inn spa of the Hanamaki Minami hot spring area. Legend tells of a white monkey bathing in water welling up at the foot of a katsura tree, remembered in the names of the Katsura-no-yu source and the naturally gushing Hakuen-no-yu rock bath. Fuji San Ryokan, founded in 1841, uses several sources bath by bath. This analysis covers a blend in which the cooler Shimo-no-yu is added to the hotter Katsura-no-yu to reach a comfortable temperature, feeding baths such as Shiraito-no-yu overlooking the Shiraito Falls. The weakly alkaline water feels smooth and invites deep relaxation to the sound of the river.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.2
0714
TEMP48.2℃
0℃50℃100℃
KEY MINERALS
3.0 mg/kg

A trace antibacterial component that keeps skin clean.

5.3 Bq/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

A natural moisturizer that leaves a hydrated feel on the skin.

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Yuyado Tokinoniwa Sulphur Spring
Sulphur SpringAcidic SpringChloride SpringSulphate SpringVerified
Yuyado Tokinoniwa
湯宿 季の庭
Gunma Kusatsu· わたの湯 他 1 件Kusatsu Onsen
The Cotton-Wrapped Spring

This rare, naturally gushing source emerges from beneath 'Gensenkaku,' nestled beside Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field). Despite its strong acidity, its waters offer a remarkably soft bathing sensation, akin to being enveloped in silk floss. The milky-white waters, renowned for having Kusatsu's finest 'yunohana' (hot spring minerals), gently embrace the skin, contributing to silky skin and providing a restorative warmth that lingers deep within the body. Known as a 'phantom spring' for its history of disappearing once during the Taisho era, it now offers a profound escape from daily life, inviting deep relaxation and rejuvenation.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2.1
0714
TEMP50.2℃
0℃50℃100℃
KEY MINERALS
44.3 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

9.6 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

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Kinosaki Onsen Fujimiya Chloride Spring
Chloride SpringInfo pending
Kinosaki Onsen Fujimiya
城崎温泉 富士見屋
Hyogo 豊岡市· 城崎温泉 集中管理混合泉
The Town-Wide Salt Spring

Kinosaki Onsen's centrally managed mixed spring gathers water from several wells into a large storage tank, where its temperature is steadied before it flows through a looped pipe beneath the streets to the town's public bathhouses and inns. Managed as a shared resource by the Yushima property ward of Kinosaki, this faintly salty water wraps the body in warmth that lingers long after bathing, suiting travellers who stroll from bath to bath in yukata.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral7.3
0714
TEMP62.1℃
0℃50℃100℃
KEY MINERALS
70.0 Bq/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

2460 mg/kg

Boosts after-bath warmth and warms the body from the core.

8.0 mg/kg

Gentle calming action; often found alongside chloride.

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Kusatsuonsen Ichii Acidic Spring
Acidic SpringChloride SpringSulphate SpringSulphur SpringInfo pending
Kusatsuonsen Ichii
ホテル一井
Gunma Kusatsu· 万代鉱 他 1 件Kusatsu Onsen
The Strongest Spring from the Mine

The Bandaiko source, which unexpectedly erupted from within the Bandai Sulfur Mine in 1970, now stands as Kusatsu's primary hot spring, boasting the largest output and supporting the town. Named with the wish for 'eternal prosperity' (万代), this powerful source was born in the mountains, far from the Yubatake (Kusatsu's central hot-water field). Its colorless, transparent waters deliver a stimulating tingle that awakens both mind and body, while its robust warmth permeates to the very core. This energetic spring is a perfect companion for those seeking liberation from daily routines and a crisp mental and physical rejuvenation.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic1.7
0714
TEMP94.6℃
0℃50℃100℃
KEY MINERALS
43.2 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

25.1 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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Sukayu Acidic Spring
Acidic SpringSulphur SpringFerruginous SpringSulphate SpringChloride SpringInfo pending
Sukayu
酸ヶ湯
Aomori Aomori· 酸ヶ湯温泉(熱湯) 他 2 件Sukayu Onsen
The Strongly Acidic Heart of the Spa Retreat

This spring rises at a spa retreat about 900 m up the northwest flank of the Hakkoda Mountains, amid beech forest, in the area chosen as Japan's first National Health Resort Hot Spring. It has long filled a great bathhouse built entirely of hiba cypress alongside the area's other springs. At pH 1.71 it is strongly acidic, with a tingling bite on the skin and a faint scent of sulfur and iron; sinking into its milky water feels like the essence of a traditional healing spa, especially in deep-snow winter.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic1.71
0714
TEMP48.8℃
0℃50℃100℃
KEY MINERALS
212 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

53.1 mg/kg

An iron-rich spring whose water turns yellow-brown to red-brown when exposed to air. Strong heat retention.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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An Bar Yufu Inn Chloride Spring
Chloride SpringCarbonated SpringInfo pending
An Bar Yufu Inn
AMBER Yufuin
Oita Yufu· AMBER Yufuin
The Amber Moisture Spring

This is a newly drilled source in the Yufuin Onsen area, which boasts one of the largest outputs in Japan. Nestled at the foot of Mt. Yufu, this hot spring resort has long been cherished for therapeutic bathing. The AMBER Yufuin source features a high alkalinity of pH 8.9, combining the qualities of a bicarbonate spring that smooths the skin by removing old keratin, and a chloride spring that helps retain body heat. It is particularly characterized by its abundance of metasilicic acid, a natural moisturizing component.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.9
0714
TEMP68.1℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

A trace component with gentle antibacterial and anti-inflammatory action.

Softens dead skin cells for a silky bathing feel.

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Tajimayaryokan Sulphur Spring
Sulphur SpringAcidic SpringChloride SpringSulphate SpringInfo pending
Tajimayaryokan
草津温泉 田島屋旅館
Gunma Kusatsu· 湯畑源泉Kusatsu Onsen
The Cure-All Spring

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2
0714
TEMP52.3℃
0℃50℃100℃
KEY MINERALS
49.1 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

10.1 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

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Usuki Yu no Sato Yakushi no Yu Chloride Spring
Chloride SpringCarbonated SpringInfo pending
Usuki Yu no Sato Yakushi no Yu
臼杵 湯の里 薬師の湯
Oita Usuki City· 臼杵温泉
Slippery Spring of the Stone Buddhas

Usuki Onsen was drilled to 1,300 m near the old castle town of Usuki, long known as a place without hot springs. Formerly called a "bicarbonate-salt spring", it emerges colorless and clear with a faint salty taste. Its weakly alkaline bicarbonate softens the skin surface for a remarkably slippery feel, while the chloride keeps warmth lingering after the bath. It suits travelers who want to warm up gently after strolling the stone Buddhas and castle-town lanes.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.1
0714
TEMP25.5℃
0℃50℃100℃
KEY MINERALS
64.5 mg/kg

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

13.3 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

Softens dead skin cells for a silky bathing feel.

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Shikaribetsu-ko Onsen Hotel Fuusui Chloride Spring
Chloride SpringCarbonated SpringInfo pending
Shikaribetsu-ko Onsen Hotel Fuusui
然別湖畔温泉ホテル風水
Hokkaido Shikaoi· 然別湖畔温泉(源泉名 然別湖畔温泉ホテル1号井)Lake Shikaribetsu Onsen
Yellow-Green Waters on a Highland Lakeshore

Lake Shikaribetsu, at about 800 m, is Hokkaido's highest natural lake. Hot-spring rights on its shore changed hands in the 1920s and an inn opened in 1931; natural outflows were used until around 1965, after which water was drawn from drilled wells. Clear at the source, it turns a cloudy yellow-green in the tub and stains the floor brown with mineral deposits. A faint sulfur scent, an iron-tinged carbonate taste and a smooth, slippery feel mark the water, and in winter an ice-top open-air bath appears on the frozen lake.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.3
0714
TEMP53.9℃
0℃50℃100℃
KEY MINERALS
85.4 mg/kg

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

Absorbed through the skin to gently promote peripheral circulation.

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Unga no Yado Otaru Furukawa Chloride Spring
Chloride SpringInfo pending
Unga no Yado Otaru Furukawa
運河の宿 おたる ふる川
Hokkaido Otaru· 運河の宿 おたる ふる川
Warming Spring by the Canal

Drilled beside the Otaru Canal, lined with Meiji-era stone warehouses, this source is pumped up at 330 liters per minute. Though it emerges as a 20.5°C cold mineral spring, its chloride-rich water, once warmed, wraps the skin softly and lets warmth linger long after the bath. It suits travelers who want to steep away the chill after strolling the canal-side streets.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline7.5
0714
TEMP20.5℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer that leaves a hydrated feel on the skin.

937 mg/kg

Boosts after-bath warmth and warms the body from the core.

562 mg/kg

Gentle warming effect that helps you stay warm after bathing.

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Betutei Senjuan Sulphate Spring
Sulphate SpringChloride SpringInfo pending
Betutei Senjuan
別邸 仙寿庵
Gunma Minakami· 鞍置の湯・河鹿の湯・仙寿の湯 混合泉Minakami Onsen-go
Tanigawa Three-Source Stream Spring

Tanigawa Onsen rises along a clear mountain stream at the foot of Mount Tanigawa and has long been called "Mimosuso no Yu", after a legend that the goddess Konohanasakuya-hime turned the river into hot water by washing the hem of her robe. This water is a blend of three pumped sources of differing temperatures. Clear and colourless, balanced between sulfate and chloride, it wraps the body softly and suits those who wish to soak quietly while gazing at snowy or verdant river views.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.4
0714
TEMP41.4℃
0℃50℃100℃
KEY MINERALS
10.6 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

A natural moisturizer that leaves a hydrated feel on the skin.

1.5 mg/kg

A trace antibacterial component that keeps skin clean.

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Ryokan Nagasawa Heihachi Chloride Spring
Chloride SpringSulphate SpringInfo pending
Ryokan Nagasawa Heihachi
旅館 永澤平八
Yamagata 尾花沢市· 銀山温泉 協組2号・3号・6号源泉(混合)
Flower-Flecked Waters of the Silver Valley

Ginzan Onsen is said to trace its origins to waters found by miners of the Nobesawa silver mine, which flourished in the Edo period, and the town still carries the mine's name. This blend of cooperative sources No. 2, 3 and 6 rises at 63.8°C, layering sodium and chloride with sulfate, and white mineral flakes drift softly through it. Rich in metaboric and metasilicic acid, it leaves the skin moist and the body warm long after bathing, suiting those who want to warm to the core in a riverside town lit by gas lamps on snowy nights.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.6
0714
TEMP63.8℃
0℃50℃100℃
KEY MINERALS

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

A natural moisturizer that leaves a hydrated feel on the skin.

3.9 mg/kg

A trace antibacterial component that keeps skin clean.

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Tōgō Onsen Kokumin Shukusha Suimei Sō Chloride Spring
Chloride SpringSulphate SpringInfo pending
Tōgō Onsen Kokumin Shukusha Suimei Sō
東郷温泉 国民宿舎 水明荘
Tottori Yurihama· 東郷温泉2号源泉・水明荘(混合泉)
Sunset Lakeside Salt Spring

Tōgō Onsen grew up on the shore of Lake Tōgō, where hot water is said to rise even from the lakebed, and together with Hawai Onsen across the water it forms a lakeside spa district. The blend of two sources emerges at 47.9°C, clear yet rich in both salt and sulfate, pairing a skin-wrapping warmth with a refreshing finish. It suits travelers who want to sink slowly into the water while the lake glows at sunset.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline7.9
0714
TEMP47.9℃
0℃50℃100℃
KEY MINERALS
7.3 mg/kg

A trace antibacterial component that keeps skin clean.

8.5 Bq/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

A natural moisturizer that leaves a hydrated feel on the skin.

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Yoshiikeryokan Chloride Spring
Chloride SpringInfo pending
Yoshiikeryokan
吉池旅館
Kanagawa Hakone· 湯本温泉 台帳番号 湯本 第12、72、84、89、99、112号混合泉Hakone Onsen
Hakone's Historic Blended Spring

Nestled in the Hakone Yumoto area, Yumoto Onsen (a blend of sources No. 12, 72, 84, 89, 99, and 112) is a luxurious fusion of six distinct springs. It symbolizes the abundant water volume of Yumoto, which historically thrived as one of the ancient Hakone Seven Hot Springs. The chloride spring water, enveloping the skin like a delicate veil, delivers restorative warmth deep into the body's core. The lingering, cozy sensation after bathing gently promotes deep relaxation, easing away daily fatigue. This spring is recommended for those seeking to deeply warm their body and mind and indulge in tranquil moments.

Onsen RyokanPrivate Rental BathRoom with Open-air BathTattoo OK (public bath)
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.1
0714
TEMP63℃
0℃50℃100℃
KEY MINERALS
40.4 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

1570 mg/kg

Boosts after-bath warmth and warms the body from the core.

A natural moisturizer that leaves a hydrated feel on the skin.

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Kumihama Onsen Yumoto Kan Chloride Spring
Chloride SpringInfo pending
Kumihama Onsen Yumoto Kan
久美浜温泉 湯元館
Kyoto Kumihama, Kyotango· 久美浜温泉(高温源泉) 他 1 件
Kumihama's Warming Waters

Discovered in 1992, Kumihama Onsen, drilled from 1500m underground, emerges in the scenic Kumihama Bay area of northern Kyoto Prefecture, facing the Sea of Japan. Its colorless, transparent, and mild waters are renowned for a gentle, skin-enveloping veil of salt. This unique quality delivers restorative warmth deep into the body's core, ensuring a lasting sense of comfort long after you leave the bath. It's an ideal retreat for those seeking deep relaxation and a profound escape from daily life amidst stunning rias coastlines.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.08
0714
TEMP51.2℃
0℃50℃100℃
KEY MINERALS
2278 mg/kg

Boosts after-bath warmth and warms the body from the core.

10.1 mg/kg

Gentle calming action; often found alongside chloride.

889 mg/kg

Gentle astringent action that conditions the skin.

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Beppuonsen Tenkuutoubou Seikaisou Carbonated Spring
Carbonated SpringChloride SpringInfo pending
Beppuonsen Tenkuutoubou Seikaisou
別府温泉 天空湯房 清海荘
Oita Beppu· 別府温泉 清海荘内湯Beppu Onsen
The hot spring that spins Beppu's silky skin

Gushing forth in Beppu, one of Japan's premier hot spring resorts, this water has long moisturized the skin of spa-goers. With a weakly alkaline pH of 8.2, the water gently envelops the skin like a beauty serum, softening it for a smooth feel. After bathing, you'll notice a supple texture and a warmth that radiates from your core. It's a healing spring, perfect for those seeking to reset mind and body away from daily life, or for anyone concerned about dry skin.

Onsen RyokanPrivate Rental BathRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.2
0714
TEMP52.3℃
0℃50℃100℃
KEY MINERALS

Softens dead skin cells for a silky bathing feel.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

A trace component with gentle antibacterial and anti-inflammatory action.

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Kusatsu Onsen Yubatake Soan Sulphur Spring
Sulphur SpringAcidic SpringChloride SpringSulphate SpringInfo pending
Kusatsu Onsen Yubatake Soan
草津温泉 湯畑草菴
Gunma 草津町· 湯畑源泉
The Cure-All Spring

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2
0714
TEMP52.3℃
0℃50℃100℃
KEY MINERALS
49.1 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

10.1 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

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Kounkaku Sulphate Spring
Sulphate SpringCarbonated SpringChloride SpringInfo pending
Kounkaku
香雲館
Gunma Shibukawa· 伊香保温泉 総合湯(黄金の湯)Ikaho Onsen
Golden Waters of Ikaho

Ikaho is an ancient spa praised in the Man'yoshu poetry anthology. In the Warring States era its stone-step street was laid out as a healing retreat for soldiers wounded at Nagashino, and the koma-guchi system that divides the spring water among the inns survives today. Kogane-no-yu rises clear, but its iron oxidizes in the air and tints the water tea-brown, as its golden name suggests. This neutral water rich in sulfate and bicarbonate warms the body to the core and has long been called a spring for fertility. It is a bath that carries Ikaho's history itself.

Onsen RyokanRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.4
0714
TEMP41.2℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

A trace component with gentle antibacterial and anti-inflammatory action.

Softens dead skin cells for a silky bathing feel.

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Shogetsu Grand Hotel Chloride Spring
Chloride SpringInfo pending
Shogetsu Grand Hotel
章月グランドホテル
Hokkaido Minami Ward, Sapporo· 定山渓温泉Jozankei Onsen
Toyohira River Spring

Since its discovery in 1866 by the ascetic monk Miizumi Jozan, Jozankei Onsen has been cherished as Sapporo's secluded hot spring retreat. Its springs, naturally gushing approximately 8,600 liters per minute from the riverbed near Tsukimibashi and Takayamabashi on the Toyohira River, are colorless, clear, and possess a subtly salty taste. This water envelops the skin like a delicate veil of salt, delivering restorative warmth deep into the body's core. It is highly recommended for those seeking deep relaxation and liberation of mind and body, away from urban clamor, while immersed in the valley's changing seasons.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.4
0714
TEMP77.5℃
0℃50℃100℃
KEY MINERALS

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

1492 mg/kg

Boosts after-bath warmth and warms the body from the core.

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Pashipikku Onsen Hoteru Seiryuen Chloride Spring
Chloride SpringSulphate SpringInfo pending
Pashipikku Onsen Hoteru Seiryuen
パシフィック温泉ホテル清龍園
Hokkaido Yakumo· 上の湯温泉(源泉名 湯元 清龍園)
A Rich Salt Spring Gushing at 98°C in the Hills

Kaminoyu Onsen is a quiet spa in the hills beyond central Yakumo. Seiryuen's spring gushes naturally at 98°C and 60 liters per minute; because it is so hot, the water is tempered with added water, yet both indoor and outdoor baths are free-flowing. The salty water can turn faintly milky, and in the open-air bath a long hose is used to cool it on the way in.

Onsen RyokanRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8.4
0714
TEMP98℃
0℃50℃100℃
KEY MINERALS

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

Softens dead skin cells for a silky bathing feel.

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Kusatsu Kan Sulphur Spring
Sulphur SpringAcidic SpringChloride SpringSulphate SpringInfo pending
Kusatsu Kan
草津館
Gunma Kusatsu, Agatsuma District· 白旗源泉 他 1 件Kusatsu Onsen
Shirahata-no-yu of Kusatsu

Shirahatage Genzen, located in Kusatsu Onsen and adjacent to Yubatake (Kusatsu's central hot-water field), is said to have been discovered by Minamoto no Yoritomo. Historically, it served as the stage for 'Jikan-yu' (timed bathing), supporting balneotherapy culture, and is truly considered the soul of Kusatsu. Its distinctive aroma and powerful waters, which feel as though they firm the skin, seem to awaken the mind and body from within. Surrendering to its embrace offers a pure moment to shed daily clamor and rediscover one's true self. This spring is a sanctuary for those seeking a fresh start and rejuvenation.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2
0714
TEMP51.9℃
0℃50℃100℃
KEY MINERALS
47.1 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

10.0 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

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Jihou Onsen Chloride Spring
Chloride SpringInfo pending
Jihou Onsen
寺宝温泉
Niigata Nagaoka· 寺宝温泉 あわの湯
Bubbly Amber Lukewarm Spring

This source is said to have been drilled by a former well-boring contractor on spare land beside his home, seeking water for his own recovery. From 1,200 m down it is piped straight into the bottom of the baths without touching air, so fine bubbles swirl constantly and cling to the skin. Faintly amber, with an iron scent and a hint of salt, its temperature around 40°C invites long, unhurried soaks for those who enjoy the fizzy touch.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline8
0714
TEMP40.7℃
0℃50℃100℃
KEY MINERALS
6.2 mg/kg

Trace component with antibacterial and anti-inflammatory action.

Softens dead skin cells for a silky bathing feel.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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Suizantei Club Jouzankei Chloride Spring
Chloride SpringVerified
Suizantei Club Jouzankei
翠山亭倶楽部定山渓大浴場
Hokkaido Minami Ward, Sapporo· 翠山亭倶楽部定山渓Jozankei Onsen
A Private Spring Retreat

The waters of Jozankei Onsen, Sapporo's secluded retreat opened by the mountain ascetic Miizumi Jozan, are characterized by their smooth texture that gently envelops the skin. Drawn by pump-lifted methods, these therapeutic waters create a "salt veil" that thoroughly warms the body to its core, providing restorative warmth that lingers long after your bath. It's an ideal escape for those seeking deep relaxation for mind and body, allowing one to reflect on Jozankei's pristine landscapes away from the daily hustle.

Onsen RyokanRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.45
0714
TEMP62℃
0℃50℃100℃
KEY MINERALS

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

1359 mg/kg

Boosts after-bath warmth and warms the body from the core.

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Namikawa Onsen; Fukushima-ya Sulphur Spring
Sulphur SpringCarbonated SpringSulphate SpringInfo pending
Namikawa Onsen; Fukushima-ya
滑川温泉 福島屋
Yamagata Yonezawa· 滑川温泉 上の湯源泉
Milky Sulfur Waters of the Gorge

Namegawa Onsen, one of the eight hot springs of Yonezawa, is a mountain healing retreat in the Azuma range said to have opened in the Edo period with permission from the Uesugi domain. The Uenoyu source gushes beside the Maekawa stream, its bluish milky-white water carrying a gentle scent of sulfur. The water feels weighty and smooth, leaving the skin soft and light after bathing. Deep in the mountains, it suits those who want a quiet soak to the sound of the gorge.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral7.1
0714
TEMP53.6℃
0℃50℃100℃
KEY MINERALS
11.7 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

Softens dead skin cells for a silky bathing feel.

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Ishida Onsen Acidic Spring
Acidic SpringFerruginous SpringSulphate SpringInfo pending
Ishida Onsen
石田温泉
Hokkaido Hakodate· 石田温泉
Mt. Esan Alum and Iron Spring

Ishida Onsen's source flows naturally on the flanks of Mt. Esan, an active volcano, and is piped about 2.5 km down, inheriting the spring once used by a highland hotel. The 1984 analysis shows pH 2.1 and 5.518 g/kg of dissolved solids, with 2,972 mg/kg of sulfate plus abundant aluminum and iron, in the lineage of classic alum and green-vitriol springs. Clear at the source, the water oxidizes to a cloudy yellow-brown in the bath, with a squeaky feel, sour taste and metallic scent that speak of the volcano.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2.1
0714
TEMP42.5℃
0℃50℃100℃
KEY MINERALS
433 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

156 mg/kg

An iron-rich spring whose water turns yellow-brown to red-brown when exposed to air. Strong heat retention.

50.6 mg/kg

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

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Sakazuki Onsen Chokaso Sulphate Spring
Sulphate SpringInfo pending
Sakazuki Onsen Chokaso
盃温泉ホテル 潮香荘
Hokkaido Tomari· 盃温泉 2号井
Mine-Born Gypsum Spring

The name Sakazuki is said to come from an Ainu word meaning ore. Hot water that welled up inside a wartime mine was piped around 1948 to an inn converted from a herring fishermen's lodge, the origin of Sakazuki Onsen. In 1962 wells were bored into the hot-water vein beneath the ore body: Well No. 1 at 221 m and Well No. 2 at 233 m. Well No. 2 is a gypsum-type spring led by sulfate with calcium and sodium, suited to anyone who wants a quiet, warming soak while gazing over the Sea of Japan and the fishing port.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHMildly Alkaline7.6
0714
TEMP43.7℃
0℃50℃100℃
KEY MINERALS

A natural moisturizer that leaves a hydrated feel on the skin.

823 mg/kg

Soothes the skin and gently improves circulation.

A trace component with gentle antibacterial and anti-inflammatory action.

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Adachiya Ryokan Takayu Onsen Adachiya Ryokan Sulphur Spring
Sulphur SpringAcidic SpringSulphate SpringInfo pending
Adachiya Ryokan Takayu Onsen Adachiya Ryokan
Adachiya Ryokan 高湯温泉 安達屋旅館
Fukushima Fukushima· 湯花沢3番・5番・6番合併Takayu Onsen
Milky Blue Sulfur Spring

The Yuhanazawa No.3, No.5 and No.6 Combined Source gathers three springs welling up in the Yuhanazawa district of Takayu Onsen, a spa said to have opened in the Keicho era and once counted among the "Three Takayu of Oshu" alongside Zao and Shirabu. Tart at pH 2.6 and scented with powdery sulfur, its water gushes from the spouts in a blizzard of white mineral flakes, steeping the tubs in a milky blue. It suits travelers seeking a genuine mountain sulfur soak.

Onsen RyokanPrivate Rental BathTattoo OK (public bath)
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2.6
0714
TEMP45.3℃
0℃50℃100℃
KEY MINERALS
29.3 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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Binatsuyu Onsen Ryokan Nikaido Acidic Spring
Acidic SpringFerruginous SpringSulphate SpringInfo pending
Binatsuyu Onsen Ryokan Nikaido
微温湯温泉 旅館 二階堂
Fukushima Fukushima City· ぬる湯
Eye-Healing Lukewarm Spring

The Nuruyu source has been known since the Kyoho era (1716-1735), welling up at about 920 m on the eastern foot of Mt. Azuma-Kofuji. This acidic sulfate water carries iron and aluminum, emerging colorless and turning yellowish-white after a day. Though only 31.8°C, it lets warmth linger slowly in the body, leaving skin cool and smooth. It suits summer bathers and anyone who loves long, unhurried soaks in a water traditionally prized for the eyes.

Onsen Ryokan
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Acidic2.9
0714
TEMP31.8℃
0℃50℃100℃
KEY MINERALS
43.2 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

34.3 mg/kg

Oxidized iron. Tints the water reddish-brown, lending a visually dramatic, "powerful" bath feel.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

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Juhachiro Ferruginous Spring
Ferruginous SpringInfo pending
Juhachiro
十八楼
Gifu Gifu City· 岐阜市長良川温泉
Cormorant River Red Spring

Gifu-shi Nagaragawa Onsen is a city-owned source rising beside the Nagara River, famed for its cormorant fishing, at the foot of Mt. Kinka. Pumped up clear from underground, the water slowly turns yellow-brown as its iron oxidizes in the air, becoming the reddish, cloudy riverside bath the area is known for. A faint iron taste and metallic aroma reveal its rich iron content. It suits travelers who watch the cormorant boats' bonfires on a summer night, stroll the old Kawaramachi streets, then sink into a rustic, robust soak.

Onsen RyokanRoom with Open-air Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.6
0714
TEMP16.9℃
0℃50℃100℃
KEY MINERALS
45.9 Bq/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

20.2 mg/kg

An iron-rich spring whose water turns yellow-brown to red-brown when exposed to air. Strong heat retention.

A natural moisturizer that leaves a hydrated feel on the skin.

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Onsen Pension Ginga Sulphur Spring
Sulphur SpringInfo pending
Onsen Pension Ginga
温泉ペンション銀河
Hokkaido Kamikawa· 銀河の湯・流星の湯・星の湯の混合Sounkyo Onsen
Three Star-Named Springs of the Gorge

Ginga no Yu, Ryusei no Yu and Hoshi no Yu are three springs that gush naturally in the national forest toward Momijidani at Sounkyo Onsen, and the blend of these three sources is piped in together. Sounkyo is a spa set in a gorge of sheer Daisetsuzan cliffs, and this blend, though hotter than 70°C, is neutral and gentle, carrying a faint hydrogen sulfide scent and an eggy taste. Its slippery touch leaves the body light, a soothing sulfur spring for anyone who wants to linger amid the gorge's wild scenery.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral7.1
0714
TEMP72.3℃
0℃50℃100℃
KEY MINERALS
17.3 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

The aroma typical of sulfur springs, with circulatory and antibacterial effects.

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Yunosaka Kurume Hotspring Sulphur Spring
Sulphur SpringInfo pending
Yunosaka Kurume Hotspring
湯の坂 久留米温泉
Fukuoka Kurume· 久留米温泉
Free-Flowing Sulfur Beauty Spring of Chikugo

Kurume Onsen rises in Yunosaka, on the eastern edge of Kurume overlooking the Chikugo Plain, where drilling in the late Showa era struck a spring that flows by its own pressure. It still gushes 94 liters a minute at over 50°C without pumps. The alkaline water carries a faint scent of sulfur and leaves a squeaky-clean, smooth feel, an unpretentious beauty bath right on the city's doorstep.

Onsen RyokanPrivate Rental Bath
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHStrongly Alkaline9.5
0714
TEMP50.4℃
0℃50℃100℃
KEY MINERALS
8.4 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

A natural moisturizer that leaves a hydrated feel on the skin.

53.0 mg/kg

Slightly alkaline, softening dead skin cells.

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Nanten-en Radioactive Spring
Radioactive SpringInfo pending
Nanten-en
天見温泉 南天苑
Osaka Kawachinagano City· 天見温泉 N-4号
Paradise Bath of the Koya Pilgrims

Said to have flowed since the Nanboku-cho period, this Amami spring is remembered in the tale of a "paradise bath" that soothed pilgrims bound for Mount Koya. Light in dissolved minerals, it is a radioactive spring carrying radon and a touch of free carbon dioxide. It suits travelers who trace the old Koya Kaido road and want a quiet soak by a clear stream.

Onsen RyokanRoom with Open-air BathTattoo OK (public bath)
StimulationBactericidalSkin BeautyHeat RetentionRelaxation
pHNeutral6.88
0714
TEMP15.3℃
0℃50℃100℃
KEY MINERALS
30.2 mE/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

Softens dead skin cells for a silky bathing feel.

A natural moisturizer that leaves a hydrated feel on the skin.

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Hot Springs for Autonomic Disorder & Stress | Guide Based on Official Indications
SYMPTOMSMay 6, 2026· 2min read

Hot Springs for Autonomic Disorder & Stress | Guide Based on Official Indications

Autonomic nervous system disorder is a general bathing indication recognised across all 10 Japanese spring types. Simple springs additionally carry a specific indication for stress relief and autonomic instability. The thermal, buoyancy, and hydrostatic mechanisms of onsen bathing are thought to shift the nervous system toward parasympathetic dominance, helping to reset mind and body.

Hot Springs for Fatigue Recovery | All 10 Spring Types
SYMPTOMSMay 6, 2026· 1min read

Hot Springs for Fatigue Recovery | All 10 Spring Types

Fatigue recovery and health promotion are general bathing indications recognised across all 10 Japanese hot spring types, from simple springs to radioactive springs. Three physical mechanisms — thermal, hydrostatic, and buoyancy — are thought to work together to flush metabolic waste, reduce swelling, and relax muscles regardless of mineral content.

Simple Springs (Tanjun Onsen): Gentle Waters for Everyone
SPRING TYPEMay 5, 2026· 1min read

Simple Springs (Tanjun Onsen): Gentle Waters for Everyone

Simple springs have dissolved components below 1,000 mg/kg and a source temperature of 25°C or above. Mild and non-irritating, they are safe for all ages. Alkaline simple springs (pH 8.5+) are famous for leaving skin silky smooth.