Oku-Oe Yanagawa Onsen

This is a rural day-use bathhouse in the mountains west of Oe town. There's a hinoki-wood indoor bath and a rock-lined one, each opening onto its own outdoor rotenburo: one is ringed with hydrangeas, the other looks out over the surrounding mountains. The men's and women's sides swap between the two every week. The water is clear, faintly salty and smooth on the skin, and it's known locally as Netsu no Yu (熱の湯), the "warming spring," because the warmth is said to stay with you long after you get out. The well here was re-drilled in September 2011, after the Tohoku earthquake stopped the original source from flowing. Out front there's a free foot bath fed straight from the spring and a drinking fountain where visitors fill a bottle to take home. There's no restaurant, but the on-site shop sells local vegetables, wild mountain greens and bread that many visitors eat in the rest areas after a soak, and the lobby has a pair of pellet stoves. A self-catering lodging annex next door is used for toji stays as well as overnight guests.