It is said that the origin of the spring dates back to 989, when Sadamitsu Usui, a retainer of Minamoto no Yorimitsu, received a divine message in a dream that he would be given a sacred spring that cures 40,000 diseases. There are also attractions such as Okushimako Lake, which is filled with vivid blue water, and a group of potholes created by the flow of the river over tens of thousands of years.