Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Tennen Onsen, known as Keika no Yu, is located in Kurume, Fukuoka Prefecture. Its sodium-chloride water reaches 40°C, with an indoor bath, an outdoor rotenburo bath and a sauna.
Insider tip — 'Keika no Yu' (蛍火の湯 — firefly-light spring, or 香花の湯 — fragrant flower spring) at Tennen Onsen in Kurume city, Fukuoka. Kurume is the birthplace of Bridgestone Tires — founder Ishibashi Shojiro (石橋 = stone bridge) started here in 1931. The city is also renowned for Kurume kasuri, the indigo-dyed ikat fabric that influenced global fashion. Kurume's alkaline thermal springs from the Chikugo plain offer the classic smooth, warming bath beloved across southern Fukuoka.