Nakanoyu Onsen Ryokan

Nakanoyu has two baths worth knowing: an indoor bath that looks out at the Kasumi-dake ridge, with water that's soft on the skin, and a small outdoor bath tucked into the surrounding beech forest. The indoor bath splits into a hot tub and a milder one; the outdoor bath tends to run lukewarm too, so bathers move between them. A family bath (kashikiri) is usually free and open without reservation in the early afternoon. It's a single mountain inn founded in 1915, rebuilt at its current spot on the Abo Pass road after a 1998 steam explosion tied to nearby tunnel construction. It's the only inn in the area that stays open all winter, doubling as a base for climbing Mt. Yakedake and for snow-season trips around Kamikochi, and it belongs to the association for Japan's secluded hot-spring inns (Hitou wo Mamoru Kai, 日本秘湯を守る会).