Yamada Ryokan

Yamada Ryokan is the only inn still standing at Otari Onsen, in the mountains of Myoko-Togakushi Renzan National Park at around 850 meters. Two of its own springs feed the baths here, kept flowing straight from the source with no added water or heat. Genyu (元湯), the old bathhouse at the center of the inn, has kept largely the same tub for over a century, with the water dropping in as a small waterfall; there's a standing waterfall massage and a lying-down soak too, and it's open around the clock except for cleaning. A short walk away, Sotoyu Tenbo-buro (外湯展望風呂) is a view bath rebuilt from a former temple hall, with separate open-air tubs for men and women looking out over the surrounding peaks (the women's side has a lattice screen for privacy), plus a small hinoki bath and shower indoors. There's also a drinking fountain for trying the water straight. Bathers describe it as soft on the skin and faintly brownish, warmer indoors than out. Six of the wooden buildings here, spanning the Edo, Meiji, Taisho and Heisei eras, are registered as national tangible cultural properties. The inn's own history goes back to 1555, when the spring is said to have been found by a retainer of Takeda Shingen during the Kawanakajima campaigns. It still runs as a toji (湯治) retreat in the old style, remote enough that visitors often mention the mountain quiet and birdsong as the first thing they notice.