Katakurakan Public Bathhouse (Kamisuwa Onsen)

Katakurakan is a historic public bathhouse in Kamisuwa Onsen, on the shore of Lake Suwa in Suwa City, Nagano, drawing on a sodium-chloride hot spring that has supplied the lakeside town's baths for over a century. The bathhouse is best known for its senninburo, a large communal stone tub built to accommodate many bathers at once, a design dating to the Taisho era that reflects the town's history as a hot spring resort for lakeside recreation rather than a therapeutic retreat. Facilities include the main indoor bathing hall and a public rotenburo with views over Lake Suwa, along with a free ashiyu foot bath in the adjacent lakeside park that is open around the clock to anyone, no admission required. Some facilities in the area also offer mineral water drinking fountains, a practice tied to the belief that the region's spring water aids digestion when consumed as well as bathed in. This is a public day-use bathhouse rather than a spa with treatment rooms or therapists; there is no massage or treatment menu, and the experience centers on the historic architecture, the mineral water, and the lake views from the outdoor bath.