Nigorigo Onsen Ryokan Yumotokan

Ryokan Yumotokan is a hot spring inn at Nigorigo Onsen in Osaka-cho, Gero City, Gifu Prefecture, standing at an elevation of about 1,800 meters on the Hida side of sacred Mt. Ontake (3,067 m). Nigorigo Onsen, once known as Take-no-yu (bath of the peak), already had lodgings in the Meiji era and has long served as a base for Ontake pilgrims and climbers. Yumotokan sits right by the Hida-side trailhead and styles itself an inn in the sky.

The water is a sodium-calcium-magnesium sulfate and bicarbonate spring (neutral, hypotonic, high-temperature) with a source temperature of 52.8 degrees Celsius. Rich in iron and minerals, the brownish water is so opaque that you cannot see your arm below the surface, and it carries a distinctive metallic scent. The baths are fed directly from the source without reheating (water is added when filling the tubs), and overnight guests can bathe 24 hours a day.

The inn offers gender-separated indoor baths and open-air baths surrounded by virgin forest, one of each for men and women. There are 13 Japanese-style rooms, and meals featuring Hida beef and hoba-miso are well regarded. Day-trip bathing is available from 12:00 to 15:00 for 600 yen per adult (advance confirmation recommended). The inn operates only in the green season, roughly April to October, and closes in winter.