Kamuiwakka Hot Falls

Mount Io, one of Shiretoko’s volcanoes, leaks hot spring water directly into a mountain stream — so the Kamuiwakka river runs warm, and the only way to experience it is to walk up the middle of it.

Why It’s Interesting

This is as close as Japan gets to a natural water park: a 500-meter wading route up a volcanically heated river inside a UNESCO World Heritage wilderness, scrambling over three waterfalls with the water getting warmer at every step — lukewarm at the trailhead, a proper bath-like 38°C at the fourth fall, where steaming spring sources vent above you. The whole thing is managed like the serious backcountry site it is: online time-slot reservations, a mandatory safety video, free loaner helmets, and rentable aqua shoes, because the mineral-slicked rock is genuinely slippery and the water acidic enough to sting a fresh scrape. Between the gravel-road approach, the bears-live-here signage, and the absurd novelty of climbing a warm waterfall, it’s the single most memorable half-day in Shiretoko for most visitors who do it.

Best Time to Visit

The river is open July through September only — August is peak, and during the Obon window (August 8-15, 2026) private cars are barred and a shuttle runs from the Shiretoko Nature Center instead.

Getting There

Base yourself in Utoro on the peninsula’s west coast; the trailhead is about 40 minutes from the Shiretoko Nature Center along an unpaved road (shuttle-only during peak August dates). Reserve your slot and rental shoes before you come.