Tsubame Onsen Kogane-no-yu (free open-air bath)
A free, gender-separated open-air bath at the top of Tsubame Onsen, a trailhead village at about 1,100 m on Mt Myōkō. Five minutes up a mountain path from the village you find only a simple plank changing hut and a rock tub, where flakes of 'yunohana' drift in milky sulphur water. Known as a 'triple beauty bath' for combining sulphur, bicarbonate and sulphate, it faces the flanks of Myōkō. Free of charge from sunrise to sunset, open April to November (closed in winter; boots needed while snow lingers); no bathing on Monday and Friday mornings for cleaning. Fifteen minutes further along the gorge is the mixed 'Kawara-no-yu' (Jul–Nov). No soap allowed and minimal changing space, so follow local etiquette. Walk from the terminus of the bus (about 21 min) from Sekiyama Station.