Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Amihari Onsen (Arineso Sanso), in Shizukuishi, Iwate Prefecture, uses sulfurous water at 44°C, with an indoor bath, outdoor rotenburo and sauna.
Insider tip — Arineso Sanso mountain lodge serves the Amihari volcanic valley of Shizukuishi-cho where the sulfurous springs share their volcanic heritage with Iwate-Komaga-take, the composite volcano rising 2,038 metres above the Kitakami highland. The Koiwai Farm apple orchards and cheese workshops visible from the spring valley produce some of Tohoku's most celebrated dairy products, maintaining the pastoral vision of Meiji-era agricultural modernisation in a spectacularly volcanic landscape.