Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Hokkitsu Onsen (Bando no Yu), in Shibukawa, Gunma prefecture, draws sulfurous water at 44°C. The facility includes an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — In the Bando (eastern Japan) gateway city of Shibukawa, where the old Nakasendo highway crossed the Tone River corridor, Bando no Yu channels the volcanic sulfurous waters that made Gunma a hot spring paradise; the surrounding Gunma mountain approaches — toward Minakami, Ikaho, and ultimately the Kusatsu caldera — create Japan's most thermally active day-trip circuit from the Tokyo metropolitan area.