Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Horita Onsen, in the hot-spring region of Beppu, Oita Prefecture, draws sulfurous thermal water at 44°C. Bathers can use an indoor bath, an outdoor bath (rotenburo) and a sauna.
Insider tip — Beppu produces more hot spring water than anywhere on Earth outside Yellowstone — over 130,000 liters per minute across eight distinct spring zones. Horita Onsen is a neighborhood sento feeding from this extraordinary geothermal system. Arrive early morning for the local custom of 'asa-yu' (morning bath), particularly popular in Beppu where hot spring use is deeply woven into daily life. The sulfurous steam rising from street grates is a constant reminder of the volcanic forces simmering underfoot.