Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
The Le Grand Karuizawa Hotel & Resort; Happu Onsen onsen, in Karuizawa, Nagano, offers thermal sulfurous water at 65°C in a setting combining an indoor bath, outdoor bath and sauna.
Insider tip — Le Grand Karuizawa Hotel & Resort is one of the most prestigious addresses in Japan's most exclusive mountain resort. 'Happu Onsen' (fortune/happiness spring) offers luxury hotel spa facilities with volcanic sulfurous waters from the Asama belt. The ideal retreat for Tokyo's discerning elite — or anyone wanting a splurge in the forest.