Yamato-no-yu

Analysis Verified
大和の湯
Earth's Effervescent Spring

Found near the Saga Yamato Interchange, "Yamato no Yu" stands as one of Kyushu's premier high-concentration carbonated springs. This source boasts an impressive 1600mg/kg of carbon dioxide gas, significantly surpassing the legal definition for a carbon dioxide spring of 1000mg/kg. Fresh, pump-lifted water is directly supplied, ensuring its purity. As you immerse yourself in the lukewarm bath, countless silver bubbles envelop your skin, their gentle effervescence stimulating circulation throughout your body. It's an ideal hot spring for those seeking deep relaxation and rejuvenation for both mind and body.

AI Generated
This source matches 2 spring types· Tap to switch
SPRING TYPE
Carbonated SpringRARE
aka "泡の湯"

As carbon dioxide is absorbed through the skin it enlarges capillaries, promoting circulation and warming the body.

See features & indications
Bathing indications
Cuts and grazesPeripheral circulatory failurePoor circulationAutonomic instability
Drinking indications
Gastrointestinal dysfunction

※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.

Definition :Contains 1,000 mg/kg or more of carbon dioxide.
Source: 環境省「あんしん・あんぜんな温泉利用のいろは」(監修:日本温泉気候物理医学会)Read full article
PH VALUE
6.2
Neutral
Acidic ← 07 Neutral14 → Alkaline
Neutral (pH 6-7.5) per Japan Ministry of Environment classification. The pH range gentlest on the skin, suitable for long bathing.
TEMPERATURE
25.1
Low Temperature Spring
Below body temperature; bathing will gradually cool the body.
KEY MINERALS

The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).

Bicarbonate ionSee detail
1668 mg/kg

A "beauty spring" that gently emulsifies dead skin cells, leaving skin smooth after bathing.

Free carbon dioxideSee detail
1600 mg/kg

Bubbles cling to the skin and dilate blood vessels — the "heart spring." Warms the body even at lukewarm temperatures.

Metasilicic acidSee detail
129 mg/kg

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

Magnesium ionSee detail
94.6 mg/kg

Transdermal absorption gently supports skin hydration and muscle relaxation.

Calcium ionSee detail
309 mg/kg

Gentle astringent action that conditions the skin.

CHARACTER · COMPOSITION PROFILE
1234StimulationBactericidalSkin BeautyHeat RetentionRelaxation

Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.

USAGE
Free-Flowing Onsen
Pure spring water — no dilution, no recirculation
HeatedNo
DilutedNo
RecycledNo
FilteredNo
DisinfectedNo
AdditivesNo
Note

The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.

SENSORY TEST
Color
無色透明
Smell
微弱土類臭
Taste
微弱炭酸味
EFFECTS
Spring-specific indications (bathing)
Cuts and grazesPeripheral circulatory failurePoor circulationAutonomic instabilityXeroderma
General indications (bathing)
High blood pressure (mild)Rheumatoid arthritisInsomniaDepressionChronic pain or stiffness in muscles and jointsMuscle stiffness due to motor paralysisGastrointestinal dysfunction
Contraindications
Acute illness (especially with fever)Active tuberculosisMalignant tumorsSevere heart diseaseRespiratory failureRenal failureBleeding disordersSevere anemiaAny actively progressing illnessPregnancy (especially early and late stages)
BATHING TIPS
AI Generated

At a cool 25.1°C, this spring is ideal for long, gentle soaks with minimal strain on the heart. To maximize the effects of the carbon dioxide bubbles on your skin, soak slowly without moving too much. Despite the low temperature, you'll feel warm and refreshed afterward due to improved circulation.

EFFECT STORY
AI Generated

This spring's defining feature is its 1600 mg/kg of free carbon dioxide. The CO2 is absorbed through the skin, dilating blood vessels and improving blood flow, making it ideal for those with poor circulation or high blood pressure. With a neutral pH of 6.24, it's gentle on the skin.

CAUTIONS
AI Generated

Avoid bathing if you have an active illness such as tuberculosis, a malignant tumor, or severe heart disease. Those who are pregnant, especially in the early and late stages, should refrain from bathing.

※ See the analysis data below for detailed contraindications

ANALYSIS DATAView all analysis fields ▼

Source Info

Source name
Yamato-no-yu
Spring type
含二酸化炭素-カルシウム・マグネシウム-炭酸水素塩泉
Source temperature
25.1℃
pH
6.24
Flow rate
60 L/min
Flow type
動力揚湯
Osmotic pressure
低張性

Analysis Document

Analysis date
2019-08-29
Analyst organization
一般財団法人 佐賀県環境科学検査協会
Registration No.
佐賀環第41号

Cations

Hydrogen ion H⁺
0.00 mg/kg
Lithium ion Li⁺
0.60 mg/kg
Sodium ion Na⁺
111 mg/kg
Potassium ion K⁺
12.4 mg/kg
Ammonium ion NH₄⁺
0.50 mg/kg
Magnesium ion Mg²⁺
94.6 mg/kg
Calcium ion Ca²⁺
309 mg/kg
Aluminum ion Al³⁺
0.00 mg/kg
Manganese ion Mn²⁺
0.20 mg/kg
Iron(II) ion Fe²⁺
5.7 mg/kg
Zinc ion Zn²⁺
0.00 mg/kg
Strontium ion Sr²⁺
1.3 mg/kg
Barium ion Ba²⁺
0.20 mg/kg
Copper ion Cu²⁺
0.00 mg/kg
Cadmium ion Cd²⁺
0.00 mg/kg
Total cations
0.54 mg/kg

Anions

Fluoride ion F⁻
0.00 mg/kg
Chloride ion Cl⁻
18.0 mg/kg
Hydroxide ion OH⁻
0.00 mg/kg
Hydrogen sulfide ion HS⁻
0.00 mg/kg
Sulfate ion SO₄²⁻
1.9 mg/kg
Bicarbonate ion HCO₃⁻
1668 mg/kg
Carbonate ion CO₃²⁻
0.00 mg/kg
Bromide ion Br⁻
0.00 mg/kg
Iodide ion I⁻
0.00 mg/kg
Nitrite ion NO₂⁻
0.00 mg/kg
Nitrate ion NO₃⁻
0.00 mg/kg
Dihydrogen phosphate H₂PO₄⁻
0.00 mg/kg
Metaborate ion BO₂⁻
0.00 mg/kg
Total anions
1.7 mg/kg

Undissociated Components

Metasilicic acid H₂SiO₃
129 mg/kg
Metaboric acid HBO₂
1.9 mg/kg
Total undissociated
0.13 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
1600 mg/kg
Free hydrogen sulfide H₂S
0.00 mg/kg
Total dissolved gas
1.6 mg/kg

Totals

Total dissolved substances
2.4 mg/kg
Component total
4.0 mg/kg
Evaporation residue
1.5 mg/kg

Usage

Heating
No
Dilution
No
Recycle / Filter
No
Additives
No
Disinfection
No

Indications & Contraindications

Bathing indications
Cuts and grazes, Peripheral circulatory failure, Poor circulation, Autonomic instability, Xeroderma
General indications
High blood pressure (mild), Rheumatoid arthritis, Insomnia, Depression, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
Contraindications
Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages)

Drinking

Drinkability
Not drinkable
FACILITY INFO
AI draft (unverified)
Official site
Tattoo
No tattoosTattoos are not permitted (signage on lockers).
About tattoos and onsen
Hours
Weekdays: 10:0023:00
Weekends & holidays: 10:0023:00
Morning bath: 6:30 AM - 8:50 AM
Closed days: Open all year round
Transit
15-minute drive from JR Saga Station (JR Saga Eki). Free shuttle bus available from near Comfort Hotel in front of JR Saga Station North Exit (9:30 AM - 4:30 PM, every 30 minutes past the hour, no service at 12 PM). 1-minute drive from Nagasaki Expressway Saga Yamato IC. 3-minute walk from Showa Bus Soza Bus Stop after taking Showa Bus from Saga Bus Center.
Parking
Available (340 spaces, free)
Day use fee
¥910Adults (junior high school age and above) pay weekday rates. Weekends and holidays are 960 yen. Children (3 years old to elementary school age) are 450 yen.
Facilities
Large Public BathOpen-Air BathSaunaCold BathHot Stone SpaRest AreaRestaurantPool (Summer Only)
House rules
The entire facility is non-smoking (smoking areas are located outside the building). Guests under high school age require adult supervision to use the pool. Food and drinks are not allowed in the pool area.
This information may change without notice. Please contact the facility directly for accurate details.
How Long to Stay (Toji)
Start with 2 nights / 3 days

Japan’s Ministry of the Environment notes that even a short stay refreshes you. For a full therapeutic cure, around 2–3 weeks is the guideline.

More on toji length
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Saga Yamato Onsen Amandi

From¥5,350/ person / night (tax incl.)
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Approx. lowest rate (varies by date & guests)

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The descriptions, catch phrases, and translations on this page are generated by AI (Claude). pH, temperature, and component values are OCR-extracted from the official analysis report. Learn more