Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
FerBicarbonatesManganèse
Hakutsuru Onsen, in the port city of Kobe, Hyogo Prefecture, draws iron-rich water at 41°C. The bathhouse offers an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — Hakutsuru Onsen taps iron-rich waters in the Kobe urban belt, where the Rokko Mountains push ancient groundwater to the surface with a distinctive amber color. The iron content stains bath tiles a warm ochre and has a reputedly high benefit for circulation and fatigue recovery. Being embedded in a densely populated city district, the bath functions primarily as a neighborhood sento, open late into the evening. The contrast of a wild iron-spring in a major port city is part of what makes Kobe's thermal heritage unique in western Japan.