Kamuiwakka Onsen (カムイワッカ湯の滝)

Kamuiwakka Hot Falls: Climbing the Volcanic Thermal Waterfall of Shiretoko

Located deep within the core of the UNESCO World Heritage Shiretoko Peninsula, Kamuiwakka Hot Falls (Kamuiwakka-yu-no-taki) is a destination that redefines the concept of a hot spring. This is not a traditional indoor bath, but a living geothermal river where an active volcano, Mount Io, heats an entire cascading waterfall. The name “Kamuiwakka” means “Water of the Gods” in the Ainu language, and for those who make the journey, it offers a primitive, exhilarating experience found nowhere else on earth. Visitors must wade through the warm, acidic currents and scale the smooth volcanic rocks of the riverbed to reach natural pools formed in the tiers of the falls. Surrounded by primeval forest and overlooking the Sea of Okhotsk, Kamuiwakka provides a raw, multisensory encounter with the volcanic heart of Hokkaido.

Key Information

The Healing Waters: Volcanic Acidity and “Hot Water Fall” Science

The waters of Kamuiwakka are scientifically unique for their extreme acidity and geothermal heat. Fed directly by the active fumaroles of Mount Io, the water has a pH level of approximately 1.3 to 1.8—comparable to diluted stomach acid. This intense acidity makes the water a powerful natural antiseptic, historically used by the Ainu for treating stubborn skin conditions and infections. As the mineral-rich water flows down the rocky stairs of the gorge, it maintains a comfortable temperature of 30°C to 38°C depending on the distance from the source. The high concentration of sulfur and aluminum ions gives the water a slightly milky, emerald tint. Climbing the falls acts as a form of “Full-Body Hydrotherapy,” where the movement against the warm current stimulates the lymphatic system while the minerals provide a deep, natural peeling effect for the skin.

How to Experience the Falls

• The Trailhead: The journey begins at the shuttle bus drop-off point. There is a simple portal where staff check your reservation and provide a safety briefing about brown bears and river etiquette.
• The Lower Falls (Ichino-taki): The most accessible area, perfect for those who want to feel the warmth of the water without a steep climb. The pools here are shallow and easy to enter.
• The Upper Tiers: For those with proper river shoes, climbing to the second and third tiers reveals larger, deeper natural basins where you can soak while watching the steam rise against the background of the Shiretoko mountain range.
• Marine Viewing: For those who cannot make the physical climb, many Shiretoko sightseeing cruises from Utoro Port pass by the mouth of the Kamuiwakka River, allowing you to see the steaming water falling directly into the Sea of Okhotsk.
• Trailhead Amenities: Note that there are no toilets or shops at the falls; a temporary changing tent is provided, but guests are advised to arrive in their swimwear under their clothing.

Must-Visit Nearby Spots

Combine your visit with the Shiretoko Five Lakes (Shiretoko Goko), located just 20 minutes away by bus. The elevated boardwalk provides a safe way to view the caldera landscape. Another essential stop is Cape Puyuni, which offers the best sunset view over the Okhotsk drift ice zones. For those wanting a deeper dive into the park’s history, the Shiretoko World Heritage Conservation Center in Utoro provides fascinating exhibits on the brown bear ecosystem and the preservation of the “Gods’ Water.”

Local Gastronomy & Souvenirs

Utoro, the gateway town, is a seafood paradise. Try the Shiretoko Salmon Roe Bowl (Ikura-don) or the locally caught “Tokishirazu” (Seasonal Salmon). A unique local treat is Haskap Soft Serve Ice Cream, made with northern berries. For souvenirs, look for Shiretoko-themed apparel from the local “The North Face” concept store and hand-carved wooden bear figurines created by local Ainu artisans. Don’t miss the “Kamuiwakka Salt,” a mineral seasoning inspired by the volcanic riches of the region.

Cultural & Historical Context

In Ainu mythology, Kamuiwakka was believed to be the path used by the mountain spirits to descend to the sea. The area was left entirely untouched for centuries due to its rugged geography. In the modern era, it became a legendary destination for backpackers in the 1980s before strict access controls were introduced to protect the fragile ecosystem. Today, Kamuiwakka is a global model for Sustainable Adventure Tourism, where limited daily entry ensures that the “Water of the Gods” remains pristine for future generations.

Practical Travel Tips

Transportation: Private cars are **restricted** during the peak August period; the “Shiretoko Shuttle Bus” is the only way to reach the falls during these times. Gear: You MUST wear “river shoes” (rubber-soled socks or sandals with straps) as the riverbed is extremely slippery; flip-flops are not allowed for safety. Reservation: Starting in 2025, **advance online booking for the bus and waterfall entry** is mandatory to prevent overcrowding. Wildlife: This is a high-density brown bear zone; carry a bear bell and follow the rangers’ instructions. Eye Protection: The water is highly acidic; avoid getting it in your eyes as it will sting severely.

2025-2026 Latest Updates

For the 2026 summer season, Shari Town has announced a new **”Kamuiwakka Digital Guide App”** that uses AR (Augmented Reality) to show Ainu legends associated with specific tiers of the falls. Additionally, the **”Shiretoko Nature Pass”** will be updated in late 2025 to include a combined ticket for the shuttle bus and a whale-watching cruise from Utoro Port, providing a more seamless experience for international tourists.

Safety & Manners

In the river, avoid using any soap, shampoo, or chemicals, as the water flows directly into the protected marine area. Always yield the path to those climbing down the rocks. If you see a bear, do not run; remain calm and follow the “Backing Away” protocol established by the park rangers. Finally, please pack out all of your trash and help maintain Kamuiwakka as the most wild and sacred thermal wonder of the north.