Oyunuma River Natural Footbath

Above Noboribetsu's main street, Jigokudani steams and bubbles inside an old explosion crater. Keep walking past the lookout and the Oyunuma River trail drops into the forest beside a stream of hot water that overflows from the Oyunuma crater pond, where sulphur spring erupts from the bottom at around 130°C.

Near Taisho Jigoku the stream widens and there's a wooden platform where people pull off their boots and lower their feet straight into the flow. The water is warm and faintly sulphurous, and the current keeps pulling fresh heat past your ankles while steam drifts off into the trees.

In winter the Oyunuma car park shuts, so the walk in from Jigokudani is the way. Carry a small towel and dry socks in your jacket. The tourism association closes the trail now and then for repairs and posts the dates on its website.