Osawa Onsen (Sansuikaku)

Osawa Onsen is a sprawling complex with over 200 years of history, consisting of a modern hotel (Sansuikaku) and a rustic, traditional thatched-roof wing (Tojiya). It is best known for 'Osawa-no-yu', a large mixed-gender outdoor bath located directly on the banks of the Toyosawa River. The bath is visible from the bridge crossing the river, highlighting the area's relaxed and traditional bathing culture. The complex offers numerous bathing options, including gender-segregated indoor baths with floor-to-ceiling windows and a historic semi-outdoor bath called 'Yakushi-no-yu'. It has long been a favorite for 'toji' (prolonged hot spring healing stays). The atmosphere is a blend of refined hospitality and gritty, authentic history.