Wakoto Onsen

The Wakoto Peninsula juts into the south side of Lake Kussharo, and at its base there's a free rotenburo with a simple changing shed, open around the clock. The water is a neutral simple spring that leaves the ground at 52.5°C.

Walk ten minutes out along the peninsula path and there's a free communal bath that often runs too hot to sit in, especially in summer. Five minutes past that, on the lake edge, is the wild pool locals call Keigetsu-no-yu. Out at the tip near Oyakotsu Jigoku the springs boil at close to 100°C, and bathers mix in lake water to make it bearable.

Two campgrounds sit by the peninsula and fill with families in summer. In winter you'll want a base in Kawayu or Teshikaga and a car with good tyres.