Located in the Sierra Hotel near Tsugaike Resort, Mizubasho Onsen is the largest hot spring in the Hakuba Valley and is one of the few 100% Gensen-Kake-Nagashi, meaning it’s 100% pure with no added tap water or additional heating.
The surrounding forest area is rich in geothermal energy and over 200 liters of mineral water is pumped from the surrounding area every minute and distributed between the indoor and outdoor baths. Though the Onsen is relatively new having opened in 2012, it was constructed using timbers from traditional housing as old as 160 years, creating an aesthetic and experience of ancient Japan.