照湯泉源
Teruyu Spring Source湯
Simple
Sodium Chloride-Bicarbonate-Sulfate spring
Hot source · 98°C
Composition fingerprint0.1 g/kg dissolved · Hypotonic
Na⁺65
Ca²⁺18
Cl⁻43
HCO₃⁻37
SO₄²⁻20
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Chloride Cl⁻
- table-salt anion — coats the skin and holds heat in.
Known good for
- Aches & jointsstiff shoulders
- Recoveryfatigue, stress
A simple thermal spring that emerges at 98.1 °C — among Japan's hottest natural sources. The water itself is very lightly mineralized, at just 99 mg/kg of dissolved solids, and close to neutral at pH 6.5, so it is gentle on the body rather than assertive. Because the wellhead runs so hot, the posted notice states the bath is diluted with water, reaching the bathing point at around 53 °C. The panel lists the water for neuralgia, muscle and joint pain, cold sensitivity and fatigue recovery, and flags that drinking is not permitted without a separate license.
Analyzed May 8, 2003·大分県衛生環境研究センター