Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Nyu Onsen, in Ōita, Oita Prefecture, draws a particularly hot sulfurous thermal water, at 48°C. The facility offers an indoor bath, an outdoor bath (rotenburo) and a sauna for a full soak.
Insider tip — Nyu Onsen ('entry' spring) in the Oita city area, within the world's most geothermally active region outside of Iceland. Every neighbourhood in Oita-Beppu seems to have its own onsen — a result of the extraordinary density of geothermal vents in the Beppu volcanic system.