Create Your Own Natural Hot Spring Bath
Dig into the Riverbed and Make Your Own Bath
The most distinctive feature of Kiriake Kawara-yu is that you can dig your own open-air bath. Shovels are used to dig into the gravel of the riverbank, where naturally heated hot spring water bubbles up from beneath the riverbed.
Once a suitable pool has been created, clear water from the Nakatsugawa River can be allowed to flow into it to adjust the temperature. In this way, visitors can create their own temporary natural hot spring bath. Feeling the warm spring water emerge directly from beneath you is a unique reminder that this is a genuine natural hot spring.
Soaking in the bath while listening to the sound of the river, breathing the clear mountain air, and looking up at the surrounding valley creates an experience that is completely different from visiting an ordinary hot spring resort. Here, the landscape itself becomes part of the bath.
Important Safety and Bathing Etiquette
Because the bath is located directly beside a natural river, it must not be used when the river level is high. Weather and river conditions should always be checked carefully before entering the area.
The river bath is also a mixed-gender bathing area, so wearing a swimsuit is required. Guests staying at Hatago Ogawakaku in Kiriake Onsen can borrow shovels, making it easier for first-time visitors to enjoy the experience.
The Hot Spring and Kiriake Onsen
Hot Spring Water Flowing from the Riverbank
The spring water at Kiriake Onsen is classified as a calcium-sodium chloride and sulfate spring, with a source temperature of approximately 54.7°C. Because the water is naturally very hot, river water is mixed into the pools at Kawara-yu to bring the temperature down to a comfortable level.
Several natural outdoor hot spring pools can be found along the left bank of the Nakatsugawa River. These wild springs are a remarkable example of a traditional Japanese hot spring culture that exists in close harmony with the surrounding environment.
Stay at Kiriake Onsen
Although Kiriake Onsen is located deep in the mountains, visitors can stay at one of three local accommodations: Kiriake Riverside House, Hikyo-no-Yado Yukiakari, and Kiriake Onsen Hatago Ogawakaku.
All three accommodations offer day-use bathing, allowing travelers to enjoy the hot spring even without an overnight stay. Their warm hospitality adds a welcoming human touch to this otherwise secluded mountain destination.
A Hot Spring with Centuries of History
From an Edo-Period Discovery to a Modern Mountain Retreat
Kiriake Onsen has a long history. Records from 1722, during the middle of the Edo period, already mention the hot spring. It is said to have been discovered around 1700 by a local village headman.
The original facilities were eventually destroyed by flooding, but the hot spring was brought back to life when the village-operated Ogawakaku reopened in 1972. Today, Kiriake continues to preserve its distinctive character as a remote mountain hot spring.
Reaching This Remote Mountain Hot Spring
Access to Kiriake is part of the adventure. From Tsunan Town in Niigata Prefecture, local buses operate toward the entrance to Akiyama-go. From there, travelers can use a reservation-based shared taxi to reach the Kiriake settlement.
Public transportation is limited and the journey requires some planning, but this remoteness is an important part of what makes Kiriake Onsen special. Far from busy tourist centers, the area retains the atmosphere of an isolated mountain settlement where nature and traditional hot spring culture remain closely connected.
A Truly Wild Japanese Hot Spring Experience
Kiriake Kawara-yu offers an extraordinary way to experience a Japanese hot spring. Instead of simply stepping into a prepared bath, visitors can dig into the riverbank, watch hot spring water rise naturally from the ground, adjust the temperature with clear river water, and create their own bathing pool.
Surrounded by the mountains of Akiyama-go and accompanied by the sound of the Nakatsugawa River, the experience brings visitors remarkably close to the natural source of the hot spring. For travelers fascinated by Japan’s onsen culture and looking for an unusual experience far from the ordinary tourist route, Kiriake Kawara-yu is a memorable destination deep in the mountains of Nagano.