Indoor bath
![Indoor bath](https://images.microcms-assets.io/assets/873c9ec45c954cd3a68d88028fef0075/0c674470a08d42d09fcbbb1b21061e85/KinkiyuSUIKAZURA_Top_03.jpg)
Kawayu Onsen is a strongly acidic sulfur spring that is rare in Japan, with its source under Mt.Iou. The name Kawayu is a literal translation of the Ainu word "seseki (hot) betsu (river)", and a hot spring river flows through the hot spring town.