Yumoto Hana No Yu

Yumoto Hana no Yu is a day-use onsen and sauna complex in Hakodate, built around two garden open-air bath zones, one Japanese in style and one Western, that swap between the men's and women's sides each week. There is also an indoor bath, a cooler soaking pool, a cold plunge, and five different sauna rooms: an indoor dry sauna plus a barrel sauna, a cuberu sauna, a meditation-style sauna, and an outdoor loyly steam sauna. One of the hotter tubs runs as an electric bath, and there is a Hungarian-style salt cave to cool off in afterward. The spring water is carbonated and kept flowing rather than recirculated, with a light fizz you notice on the skin. The complex was the first in Hokkaido certified by the health ministry as an onsen health-promotion program facility. There is no restaurant, just vending machines and a rest hall with massage and beauty treatments, so the place is set up for a long, unhurried soak rather than an overnight stay.