For the brave and adventurous, the Ryu River Onsen is one of the many natural 'wild' onsen found close to Mount Nakahama, where visitors can bathe close to the mountain's thermal veins. The air can be obnoxiously sulphurous at times, with shimmering mirage. The onsen bathing portion is completely outdoors with various pools separated by rough brown rock, and only the surrounding stalks of vegetation provide any form of privacy. The showers, lockers, and other necessities are found at the quaint lodge where guests of the baths enter.
The baths are mostly self-service with an automated self-service kiosk. The occasional attendant appears to clean up and restock the facilities. There are several signposts put up to direct visitors to where they need to go, as well as warnings for the inexperienced about the heat, and a few remote contact stations if anyone needs immediate help. Even though the jungles are known for their sweltering heat, it does little to deter eager bathers and locals from enriching themselves with the bath's rejuvenating properties.