Kawanoyu-sen
Analysis UnverifiedTawarayama Onsen is said to have been found in 916, when a hunter tracking a wounded white monkey saw it healing itself in the hot water. Most inns here still have no baths of their own, so guests walk to the public bathhouses in the old toji tradition. Kawanoyu-sen carries the name of the former Kawa-no-Yu bathhouse and is marked by strong alkalinity at pH 9.9 and a faint whiff of hydrogen sulfide.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
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.
▸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.
At 41.6°C the water is close to body temperature, ideal for a slow 15–20-minute soak up to the shoulders. At pH 9.9 it softens the skin's surface, so avoid scrubbing hard; locals often skip the final rinse.
With pH 9.9 alkalinity plus 41.1 mg/kg of carbonate and 77.1 mg/kg of hydrogen metasilicate, this gentle simple spring is loved for leaving skin silky smooth and invites deep relaxation.
Strong alkalinity can dry the skin with long soaks or hard scrubbing; moisturize afterward if needed and drink water before and after bathing.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Kawanoyu-sen
- Spring type
- Alkaline Simple Hot Spring
- Source temperature
- 41.6℃
- pH
- 9.9
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2024-01-25
- Analyst organization
- 公益財団法人山口県予防保健協会
Cations
- Lithium ion Li⁺
- 0.04 mg/kg
- Sodium ion Na⁺
- 49.8 mg/kg
- Potassium ion K⁺
- 0.80 mg/kg
- Ammonium ion NH₄⁺
- < 0.05 mg/kg
- Magnesium ion Mg²⁺
- < 0.01 mg/kg
- Calcium ion Ca²⁺
- 1.2 mg/kg
- Aluminum ion Al³⁺
- 0.04 mg/kg
- Manganese ion Mn²⁺
- < 0.01 mg/kg
- Zinc ion Zn²⁺
- < 0.005 mg/kg
- Lead ion Pb²⁺
- < 0.005 mg/kg
- Strontium ion Sr²⁺
- 0.02 mg/kg
- Barium ion Ba²⁺
- < 0.01 mg/kg
- Copper ion Cu²⁺
- < 0.005 mg/kg
- Cadmium ion Cd²⁺
- < 0.001 mg/kg
- Total cations
- 0.05 mg/kg
Anions
- Fluoride ion F⁻
- 1.6 mg/kg
- Chloride ion Cl⁻
- 11.9 mg/kg
- Hydroxide ion OH⁻
- 1.4 mg/kg
- Hydrogen sulfide ion HS⁻
- < 0.1 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.30 mg/kg
- Sulfate ion SO₄²⁻
- 12.8 mg/kg
- Bicarbonate ion HCO₃⁻
- < 0.5 mg/kg
- Carbonate ion CO₃²⁻
- 41.1 mg/kg
- Bromide ion Br⁻
- < 0.05 mg/kg
- Iodide ion I⁻
- < 0.05 mg/kg
- Nitrite ion NO₂⁻
- < 0.05 mg/kg
- Nitrate ion NO₃⁻
- < 0.05 mg/kg
- Hydrogen phosphate HPO₄²⁻
- < 0.01 mg/kg
- Hydrogen metasilicate HSiO₃⁻
- 77.1 mg/kg
- Metaborate ion BO₂⁻
- 0.50 mg/kg
- Total anions
- 0.15 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- < 0.5 mg/kg
- Free hydrogen sulfide H₂S
- < 0.1 mg/kg
Totals
- Total dissolved substances
- 0.20 mg/kg
- Component total
- 0.20 mg/kg
- Evaporation residue
- 0.18 mg/kg
Usage
- Heating
- Yes（1号湯（源泉かけ流し）の浴室前掲示『温泉の成分、利用形態…』（分析 令和6年1月25日、県決定 令和6年6月18日）の利用形態『入浴に適した温度に保つため、加温しています。』（カリバー旅行記 2024-08-06 掲載写真）。2011年の日本温泉協会 温泉利用証の『加温 なし』より新しいため加温ありを採用（premises 15節）。）
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Autonomic instability, Insomnia, Depression
- General indications
- High blood pressure (mild), Rheumatoid arthritis, 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
