Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Chojabaru Onsen Ashiyu is set in Kokonoe, Oita Prefecture, on the volcanic Kuju plateau known for its steaming fumaroles. Sulfurous thermal water rises at 45°C, feeding an indoor bath, an outdoor rotenburo, and a sauna.
Insider tip — Chojabaru ashiyu (足湯 — free public foot bath) sits on the Kuju Highlands (九重高原) in Oita's extraordinary geothermal zone — the Kuju Volcanic Group is Kyushu's highest mountain range. The surrounding highland plateau is famous for spectacular autumn foliage (late October): crimson dwarf bamboo, golden larch and vivid maples create a tapestry across the volcanic landscape. The Chojabaru Visitor Center interprets the rare highland ecosystem.