It is a carbonated spring that springs from the historical Kisoji with a view of Ontake　mountains side to the west and Mt. Kiso-koma-gatake to the southeast. The colorless and transparent source has a unique spring quality that turns reddish brown when it comes in contact with the air. You can spend a blissful time by being healed by the murmuring of Kurokawa, the scent of the cypress in the bath and the hall.