Nozawa Onsen Ooyu Public Bath

Ooyu, meaning great hot water, is the largest and most central of the thirteen free public bathhouses (soto-yu) scattered through Nozawa Onsen, a ski and hot spring village in northern Nagano. The bathhouse sits at a crossroads in the old village core and draws directly from a high-temperature sodium-sulphate source that surfaces at around 85°C, cooled before it reaches the tub but still hot by most bathers' standards. Ooyu and its sister baths are maintained not by a company but by the village's neighborhood associations, a centuries-old system in which local households take turns cleaning and tending the water; there is no reception, no therapist, and no treatment menu, only a wooden building, a stone tub, and a donation box. The bathhouse has no pools beyond the single indoor tub, no sauna, and no lounge; its role is functional and communal rather than resort-style. Nearby, the village's public steaming vents are used by residents to boil vegetables and eggs, underscoring how thoroughly the geothermal water is woven into daily life here. Visitors are simply expected to observe the same etiquette locals do: rinse before entering, keep towels out of the water, and take a brief soak rather than lingering, since the baths are meant to serve a stream of bathers rather than one person at length.