Chloride Springs: Benefits, Indications & Recommended Onsen

The Kongoi source blends the waters of several wells at Kenichi Onsen, where dozens of springs gush along a 700-meter stretch of the Kenichi River in Kumaishi. Legend traces the spa to the Keio era of the late Edo period, when a wounded bear was seen steeping in a riverside pool; a bath keeper settled here in 1875. Nearly clear at the outlet, the water turns rusty amber as its iron oxidizes, and its salty warmth lingers long after bathing, suiting quiet, unhurried soaking.

Onsenmura No. 114, a chloride spring drawn from approximately 100 meters underground at Miyanoshita Onsen—one of Hakone's renowned Seven Hot Springs—carries a rich history. This area flourished as a therapeutic hot spring resort since the Edo period, evolving into an international destination during the Meiji era. The spring's unique feature is its gentle embrace, forming a 'salt veil' on the skin that slowly warms the body from its core. The restorative warmth lingers long after your bath, promoting deep relaxation for both mind and body. It is highly recommended for those seeking to soothe daily fatigue while immersing themselves in history.

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.

The Uwanari Gensen is a primary source for Arima Onsen's famous "Kinsen" (Golden Spring). Its name, meaning "jealousy spring," comes from a legend that the water would gush violently with envy whenever a beautiful woman passed by. [3, 6, 7] Once an intermittent spring, it is now drilled and its waters are distributed to many establishments in Arima via other sources like the Gosho Sengen. [3, 6, 7] Rich in iron and salt, this spring is known for its characteristic reddish-brown color upon oxidation and its ability to warm the body to its core.

This source, naturally gushing 200 liters per minute from the Toyohira River riverbed in Jozankei Onsen town, began supplying surrounding hot spring facilities in 1997, named after its founder, Jozan Miizumi. Its colorless, clear waters, with a faint hint of sulfur, are characterized by a gentle salt veil that envelops the skin. The heat slowly penetrates to the body's core, providing restorative warmth that lingers long after bathing. It is a renowned spring offering deep relaxation for those seeking to escape daily hustle and warm their mind and body.

Local lore says this spring was found in 1972 after a divine revelation, a story preserved in its name. Pumped from deep beneath a hillside facing Mt. Fuji and the Kofu Basin, the sodium chloride water is mildly alkaline and smooth, with a faint brown tint and a hint of sulfur, combining lasting warmth with a gentle feel on the skin.

Hot springs opened on the shore of caldera Lake Shikotsu in 1915, and until a road was built the area could be reached only by boat. It is known for a pool where water wells up through the gravel underfoot, and several sources of the same spring type flow nearby. At 50.3°C, the No. 1 Well is among the hottest. Chloride, bicarbonate and sulfate dissolve in balance, rich enough to build mineral deposits around the spout, suiting anyone who wants to warm up quietly while gazing at the lake.

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.

Housen-no-Yu, a precious spring at Kusatsu Onsen, one of Japan's three most famous hot springs, has naturally gushed from bedrock for approximately 1200 years. Distinct from major sources like Yubatake and Bandaiko, this rare water gently envelops the skin with its sulfurous aroma. Its crisp quality offers a sensation of purifying both mind and body. After bathing, your skin will feel wonderfully silky, and the restorative warmth from deep within will invite deep relaxation, supporting overall rejuvenation. It is highly recommended for those seeking to escape daily life and reset themselves with a truly special hot spring experience.

Nestled in the scenic town of Matsuyama, this spring has long been cherished for relieving traveler fatigue, boasting robust eagle-like properties. The hypertonic chloride waters envelop the skin, smoothly expelling excess fluids and metabolic waste. The lightness after bathing and deep-penetrating warmth soothe the mind and body, freeing you from daily stress. Ideal for those with chronic stiffness or cold extremities, and perfect for weekend rejuvenation.

Kintaro Onsen gushes in Tenjinno, Uozu, close to Kurobe-Unazukionsen Station on the Hokuriku Shinkansen, where the edge of an alluvial fan looks up to the Tateyama range. The Kintaro Onsen source unites the qualities of a chloride spring and a sulfur spring: a dense, hypertonic water holding 4790.0 mg/kg of sodium and 1401.0 mg/kg of calcium, with thiosulfate and free hydrogen sulfide lending a sulfur scent. White and grey mineral flakes drift through the water, suiting bathers who want a hot, deeply warming soak and lovers of both salt and sulfur.

Rising near Lake Kuccharo, a famed stopover for migrating swans close to the Sea of Okhotsk, Hamatombetsu Onsen has long warmed this northern lakeside town. Sodium-rich, with chloride and bicarbonate in near balance, it offers both smoothness and lasting warmth, and its unusually high metaboric acid adds a distinctive character to this quiet lakeside spring.

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.

Yasuda Onsen rises in the farmland of Yasuda, Agano, on the right bank of the Agano River with the Gozu Mountains behind it. Pumped from underground at 19.9°C and 105 liters per minute, the water was found in its 2024 analysis to carry 23,161 mg of dissolved matter per kilogram—a "strong brine" with salinity approaching that of seawater. Sodium makes up about 85% of the cations and chloride more than 90% of the anions. It also contains 34.1 mg of iodide and 84.6 mg of bromide, hinting at ancient seawater trapped in the strata as fossil brine, along with a generous 413.7 mg of free carbon dioxide. Nearly colorless and clear, it tastes strongly salty with a faint metallic edge. Think of it as a taciturn Sea of Japan fisherman: plain at first sight, yet its dense, briny strength wraps the body firmly and leaves a warmth that lingers long after bathing.

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.

Gokuraku Gensen is a source for the iconic "Kinsen" (gold spring) of Arima Onsen, one of Japan's three ancient hot springs. It was once called "Negai no Yu" (Spring of Wishes) and its history is tied to Toyotomi Hideyoshi, who had its waters channeled to his private bathhouse. The rich water, which turns a reddish-brown when exposed to air, has been cherished by therapeutic bathers for centuries. Its high salt concentration envelops the skin, providing long-lasting warmth after bathing. Steeping in this historic spring, you can feel the deep warmth that once soothed samurai warlords, offering a true escape from daily fatigue.

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.

This renowned hot spring of Jozankei Onsen traces its origins to a legend from 1897, where a wild deer was said to have healed its wounds on the banks of the Toyohira River. Rich in salt, the waters gently envelop the skin like a protective veil, delivering a soothing warmth that penetrates deep into the body's core. The pleasant, lingering warmth after bathing feels akin to being embraced by nature's blessings. This source offers a serene retreat for those seeking to unwind from daily fatigue while listening to the tranquil murmuring of the valley.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

This is a representative 'Kinsen' (golden spring) of Arima Onsen, one of Japan's three ancient hot springs. Rich in iron and salt, its waters turn a distinctive reddish-brown upon contact with air. These dense minerals provide deep, lasting warmth, while a salt veil on the skin helps retain moisture, leaving it feeling smooth. Perfect for those struggling with chronic fatigue or poor circulation, or anyone seeking to refresh mind and body. It supports those wishing to regain vitality through the power of its potent waters.

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.

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.

The Kashio no Yu No. 1 source draws seawater-strength brine from the heart of the Southern Alps, far from any coast, and the place name Kashio, "deer salt," is said to recall deer that gathered to lick the salty water. For generations this brine has been boiled down to make mountain salt. Its dense salts and gentle sulfur aroma wrap the body, letting warmth linger long after the bath. It soothes travelers who wish to steep quietly in a rare salt spring deep in a mountain village.

Yugawara Onsen, sung of in the Man'yoshu as the water that "springs forth in the valley of Dohi in Ashigari," is one of Japan's oldest recorded hot springs. The Yugawara Onsen Mixed Source (Gongenyama Service Center) blends several of the town's wells into a single supply at 61.7°C and pipes it to inns across the resort. Its chloride and sulfate content gives a soft, enveloping feel, and warmth lingers on the skin long after bathing, suiting travelers who seek quiet recovery in the hills.

The Kitamura Onsen source dates back to 1983, when drilling for winter heating at an agricultural facility site struck hot water at a depth of 893 m, surprising a Sorachi region long thought unable to yield springs above 25°C. Today the No.4 and No.5 wells, drilled in 1996 and 1997, are blended. This dense, intensely salty water wraps the skin and lets warmth linger long after bathing, ideal for chilly days.

The spring began in 1975, when a local farmer bored for hot water to warm his greenhouses and his own bath. Redrilled in 1999 to about 1,520 m, Well No. 2 now yields 73.6°C water: nearly colorless and clear, yet unmistakably salty, a dense sodium- and calcium-bearing chloride spring with a plain, sturdy character.

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.

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.

Misasa Onsen is said to have been discovered some 850 years ago when a samurai who spared a white wolf was guided to the spring in a dream, and its name is linked to the belief that "by the third morning, ailments are healed." It is known for radium springs with some of the world's highest radon levels. Gankutsu-no-Yu uses the natural rocks along the Mitoku River, and water rises on its own from the floor of each of its three tubs, sending small bubbles up around your feet.

Dake Onsen's association source feeds a spa village said to have opened in 1674. Its self-flowing water is piped several kilometers down from the slopes of Mt. Iwaki, and the local association flushes sulfur deposits from the pipes every month. Listed in Edo-period hot spring rankings, its sharply sour, sulfurous water suits travelers seeking an old-fashioned toji retreat.

Biratori has bathed in cold mineral water since 1979, first trucking in water that seeped naturally across the river. In 2011 a 1,503 m borehole was sunk at Nibutani on the Saru River, a place that still carries Ainu culture, and tapped a new cold spring. At 12.1°C and a mildly alkaline pH 8.3, it holds 22.06 g/kg of minerals, led by 6,303 mg of sodium, 2,016 mg of calcium and 13,400 mg of chloride, close to seawater in strength. Clear, colorless and intensely salty, it feels like ancient sea water sleeping deep beneath Hokkaido.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

The Shika no Yu source of Shikabe Onsen is said to have been discovered in the Kanbun era, when Ito Gengoro, who came from Tsugaru to harvest kelp, spotted a deer healing its wounds in the water. Once welling up naturally on the beach, this source still gushes at 77.5°C from beneath the fishing port. Its soft water, carrying a faint saltiness and a hint of the sea, wraps the skin and warms the body to the core, suiting travelers who wish to unwind slowly by Uchiura Bay.

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.

The Ryusenkaku Private Spring is pumped from a drilled well in Utsugidani, on the hillside of Arima Onsen, one of Japan's three oldest spa towns. It rises a pale yellowish brown, then its abundant iron oxidizes in the air and steeps the bath in Arima's signature rusty red. A brine about half as salty as seawater wraps the skin, and the warmth lingers long after bathing, suited to anyone wanting slow, deep warmth on chilly days.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

Nestled in the scenic town of Matsuyama, this spring has long been cherished for relieving traveler fatigue, boasting robust eagle-like properties. The hypertonic chloride waters envelop the skin, smoothly expelling excess fluids and metabolic waste. The lightness after bathing and deep-penetrating warmth soothe the mind and body, freeing you from daily stress. Ideal for those with chronic stiffness or cold extremities, and perfect for weekend rejuvenation.

Nukabira Gensenkyo spreads near Lake Nukabira on the east side of Daisetsuzan National Park, where each inn has its own source and all offer free-flowing water. Nukabira Onsen Hotel opened in 1929 as the Ryokan Fukushimakan, and the founding family still tends its bath. The source, which flows naturally on the grounds, is clear and nearly tasteless and odorless. With a balance of chloride and bicarbonate, it warms the body while feeling smooth on the skin. Two tubs, hot and medium, let you choose your temperature and linger in the mountain water.