Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Nishiki Onsen, in Hakodate on the island of Hokkaido, taps sodium-chloride thermal water at 41°C. Bathers can use an indoor bath, an outdoor bath (rotenburo) and a sauna.
Insider tip — Hakodate is one of Japan's most atmospheric port cities, opened to foreign trade in 1854 alongside Shimoda. Nishiki Onsen (Brocade Bath) provides the classic Hokkaido sento experience: warming sodium-chloride waters that fend off the sea cold. Rise at dawn for Hakodate Morning Market (ichiba) for the freshest ikura and uni sashimi, then take the night view cable car up Mt. Hakodate — consistently ranked one of Japan's three great night views.