They are a jigoku enough hidden-spring "Kuroyu" superior [ infernal ] and a remarkable high temperature souce of spring here to the Nyuto Onsenkyo deepest part and the Mt. Nyuto trailhead.
The jigoku of the lodge lower part, a souce of spring.
The river was pulled and it has dropped on cascading water hot springs directly.
The Kuroyu which is surrounded by a river and the mountain and is built in rich nature.