Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
FerBicarbonatesManganèse
Kanegasaki Onsen / Komako no Yu, in Kanegasaki, Iwate Prefecture, offers iron-rich water at 40°C. An indoor bath, an outdoor rotenburo, and a sauna make up this bathhouse in northeastern Japan.
Insider tip — Kanegasaki Onsen Komako no Yu offers iron-rich thermal bathing in the heart of Iwate's agricultural plain, its warm amber waters said to ease joint stiffness and fatigue. The bathhouse is a local community hub and sees a steady flow of farmers and elderly residents year-round. The gentle mineral content makes this an excellent choice for sensitive skin.