Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Kitanakajima Shin Onsen, in the Yodogawa district of Osaka, taps sodium-chloride thermal water at 41°C, with an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — Kitanakajima ('northern middle island') sits on a natural river island in the Yodo River in Osaka's Yodogawa ward — the waterway that has connected Kyoto to Osaka Bay since the Nara period, carrying court goods, rice, and culture downstream. The neighborhood retains a traditional river-town character: Kitanakajima Park's cherry blossom season along the Yodo riverbank is a beloved local celebration far from Osaka's tourist core. Shin Onsen's artesian black water serves this island community with genuine daily bath culture.