The Kamuiwakka River is a naturally hot mountain stream in the middle of the wilderness of Shiretoko National Park on Japan's northernmost main island of Hokkaido. For the first time since 2005, it has become possible for visitors to hike up the river again this year.

Due to the danger of falling rocks and rapidly increasing visitor numbers after Shiretoko's designation to an UNESCO World Heritage Site in 2005, tourists were restricted to a mildly interesting, lukewarm 140 meter long lower section of the river. However, starting in 2023, the river was reopened over a 500 meter long section, which includes multiple waterfalls and ends at the base of waterfall #4 where the water is as warm as 38 degrees Celsius (100 degrees Fahrenheit) and can be seen emerging from volcanically active areas further up the valley.

The reopening went hand-in-hand with the introduction of a new system for visiting the river, which includes a limit on visitor numbers and an admission fee of 2000 yen per person. Advance reservations are required, but can be made on the day if space is available. The season is limited to July 1 to October 1, 2023. And a visit requires careful preparation, self-responsibility and proper equipment, which includes a mandatory helmet.

The hike up the river is not easy and involves the tackling of three sizeable waterfalls, of which the final and third one requires a certain level of fitness and agility. However, the experience is amazing and typically takes about 60-90 minutes for the round trip.

Because the river's water is highly acidic, the riverbed is free of slippery plants, so that it is recommended to ascend the river inside the water rather than along the more slippery edges. In any case, be prepared to get wet at least up to your knees. Some visitors come in bathing pants and enjoy a dip in one of the natural pools along the way. Note, however, that the large pool, which used to exist at the base of the uppermost waterfall before the 2005 closure, was destroyed by falling rocks and cannot be used anymore.

Besides the mandatory helmet, which can be rented for free at the river, it is recommended to bring or rent aqua shoes for tackling the river. They are available for rent at the Shiretoko Nature Center, but not at the river itself.

The 2023 season is already nearing its end, but if you have plans to visit Shiretoko during summer, make sure to put the Kamuiwakka River onto your wishlist. Please check our information page on Kamuiwakka River for more practical details, including access.