Kamuiwakka River

Kamuiwakka River is a naturally hot river in the wilderness of the Shiretoko Peninsula, known for its hot waterfalls (カムイワッカ湯の滝, Kamuiwakka-yu-no-taki, lit. "Kamuiwakka Hot Waterfall"). It is possible for tourists to hike up the hot river, which makes for one of the best hot spring-related outdoor activities in all of Japan.

From 2006 to 2022, visitors to Kamuiwakka River were able to walk up only a 140 meter long lower section of the river due to the danger of falling rocks and to reduce the impact of tourism on the environment; however, in 2023, a 500 meter long section of the river was reopened to tourists under a new system, which limits the number of visitors and requires advance reservations and an admission fee. See more details about the admission system below.

The hike up the river takes about 30-45 minutes one way and involves climbing three waterfalls before reaching the fourth waterfall at the end of the trail. The water increases in temperature from lukewarm at the trailhead to around 38 degrees Celsius (100 degrees Fahrenheit) at the fourth waterfall, above which steaming hot spring sources can be seen. Because the water is highly acidic, the riverbed remains free of slippery plants, and it is recommended to walk up the river in the water rather than along the more slippery edge of the river.

Climbing the three waterfalls is not easy and requires a certain level of agility. Especially the third waterfall is steep and tall, and falls can result in nasty injuries. Consequently, all visitors to Kamuiwakka River need to watch a preparatory video before their visit and bring proper equipment. Helmets are mandatory and provided for free at the trailhead. Aqua shoes are recommended for climbing the river and are available for rent in limited numbers at the Shiretoko Nature Center (8:00 to 17:30, 440-1100 yen/day depending on the shoe size and whether you make an advance web reservation or not).

Expect to get wet at least to the knees. Some visitors come in bathing suits and enjoy a bath in one of the natural pools found along the river. Note, however, that the large pool, which used to exist at the base of the fourth waterfall before the 2005 closure, was destroyed by falling rocks and cannot be used anymore.