八千穂sauna

八千穂sauna is an outdoor sauna facility set in the forest near Yakōri in Sakuho, Nagano, built around wood-fired heat and natural cold water. There are nine saunas on site in total, including a cabin sauna, a barrel sauna, and a tent sauna, each with its own temperature and humidity depending on the day's wood and weather. Löyly water used for steam is natural and changes with the season, drawing on birch in spring and summer and fallen leaves in autumn.

Cooling off happens in a mountain water pool and barrel pool fed by natural spring water from the Kita-Yatsugatake range, or in the stream running past the property, which is also home to wild char. Drinking water is available on tap throughout the grounds. The site is open for day visits, not limited to hotel guests, and reservations are handled through an online booking page rather than by phone. Pricing is structured by weekday versus weekend and by length of stay, with two-hour, three-hour, and seven-hour options; the seven-hour course allows for sauna camping and barbecue. Extensions in 30-minute blocks are possible if the following time slot is free.

Occasional free aufguss sessions, called Yachiho Guss, run depending on staff availability, and fans are kept in the saunas for self-aufguss. The facility closes for the season around late November and reopens in warmer months, with Thursdays as the regular closing day. Groups of fifteen or more are asked to call ahead rather than book online.