Kashio Onsen Yumoto Yamashiokan

Yumoto Yamashiokan is a small, family-run inn tucked into the mountains of Oshika Village, Shimoina District, Nagano. Kashio Onsen is known locally as the salt spring, in a district famous for natural mountain salt called yamashio. The inn is a member of the Nihon Hitou wo Mamoru Kai (Association of Secluded Hot Spring Inns) and honors the association's stamp book.

The water is a sodium chloride strong-salt cold mineral spring (weakly alkaline, hypertonic) from the Kashio no Yu No. 1 source. Its evaporation residue is 15,000 to 25,000 mg per kilogram, which makes it very concentrated and keeps the body warm after bathing. The water is colorless and clear. No water is added, but because the spring is cold the baths are kept warm by constant circulation. The Natural Stone bath also has a source bath fed directly by the spring, with no circulation and no heating.

There are two indoor baths, the Hinoki (cypress) bath with a lying-down section and the Natural Stone bath, and men and women swap them each day. There is no open-air bath, but windows look out on the mountains. Baths are open from check-in until midnight and from 6:00 to 9:30 the next morning. Overnight rates with two meals start at 13,750 yen per person including tax, and the shop sells yamashio salt and salt sweets.