Yumura Onsen Asanoya

Asanoya has its own hot-spring source in Yumura Onsen and channels it everywhere: a large hinoki-scented indoor bath, an open-air rotenburo, a private open-air bath, and even the guest-room tubs and taps. The water is soft and slightly silky on the skin, gentle enough that the inn markets it as safe for a baby's skin, and guests can drink the spring water as well as bathe in it. Below the rotenburo sits a low-temperature geothermal sauna built into an old onsen-heated drying room, mild enough to sit in for a long stretch without feeling short of breath. The two main baths swap daily between rooms named Hikoboshi (彦星) and Orihime (織姫), after the Tanabata legend, so there's no mixed bathing. It's an old, unfussy ryokan with a dining room, a bar and parking for guests.