Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Hamana Onsen Hamamatsu is a thermal bathing destination in Hamamatsu, Shizuoka Prefecture's largest city and a powerhouse of Japanese manufacturing and musical instrument culture — home to the headquarters of Yamaha, Kawai, and Roland — situated between Lake Hamana and the Pacific Ocean on Japan's tokai coast. The naturally chloride-sodium hot spring waters here are valued for their warming and circulation-stimulating properties, offering bathers an effective recovery soak in a city known more for motorcycles and pianos than for thermal springs. Accessible and welcoming, Hamana Onsen provides urban Hamamatsu residents and visitors with a genuine geothermal wellness experience complementing the city's extraordinary industrial, musical, and lacustrine cultural offerings.
Insider tip — Hamana Onsen taps into the brackish sodium-chloride aquifer beneath the coastal lowlands near Lake Hamana, the lagoon famous for eel farming and freshwater pearl cultivation. The salt-rich water warms the body quickly and has a detectable oceanic salinity that lingers on the skin. Urban sento facilities in this district often pipe the thermal water alongside Lake Hamana bay views, pairing hot-spring culture with fresh unagi cuisine.