Kamuiwakka Hot Falls

Kamuiwakka means something like water of the gods in Ainu, and the river earns an odd version of that name: hot spring water from Mount Io runs into it, so the whole stream is warm. At the road bridge the water is about 25C. Walk upstream for about 400 m, climbing about 80 m over a chain of small falls, and at the fourth fall it is about 35 to 38C. Getting to the fourth fall takes 60 to 90 minutes there and back. In the busiest years about 100,000 people a year came for the round pool at the fourth fall. Falling rocks ended that: from 2006 everything above the second fall was closed. It reopened in July 2023, after 18 years, as a booked, paid activity, and the limit is still the pool by the fourth fall. You may not climb on to the fifth. The operator also says the pool is no longer big enough for a dozen people at once. You bathe in a swimsuit, never naked. The water is strongly acidic with sulphur, can sting sensitive skin and corrodes jewellery and electronics. There is no phone signal, and the operator says rescue takes 40 minutes or more after a call. In 2026 it counted 9 brown bear sightings, 20 rockfalls and 14 injuries on its site. The forest road was closed from June 23 to 26, 2026, until a bear near the falls was caught. Elementary school children are strongly advised to stop at the first fall, and preschoolers cannot go in. There are three portable toilets and a few changing tents, but no shop or vending machine, so bring water and a towel.