Yomogihira Onsen

Two inns and a foot bath at the mouth of the Kiyotsu gorge, counted among the three great gorges of Japan for the columnar rock walling it in. The sulfur water at Kiyotsukan is said to have been located through a vision of Yakushi Nyorai, and the inn belongs to the association that keeps Japan's hidden hot springs. Most visitors come for the gorge tunnel, whose far chamber holds a shallow pool that mirrors the cliffs.

A hamlet on the Tadami River in Oku-Aizu with one bathhouse and one minshuku, sharing a 38 °C spring so charged with dissolved carbon dioxide that it ranks among the most carbonated in Japan — tea-brown, faintly salty, lukewarm enough to sit in for an hour, and drunk as well as bathed in. A second spring rises cold a few minutes away: a well of natural sparkling water that Meiji-era traders shipped to Europe and that is still bottled today.