The soup is located in the center of Kusatsu Hot Spring. It is the source of a surrounded hot spring. The area is about the size of a football field. There are white smoke everywhere. You can faintly smell the smell of sulfur. Even if some people are not used to it, it is undeniable that it is such a unique taste. To create the quality enjoyment of Caojin Hot Spring. There are dozens of wooden boxes like tofu boxes in the middle of the soup. Generally, people may think that they are used for steaming tofu. In fact, these wooden boxes are precious, mainly in the material left after the hot spring flow, and then processed into hot spring powder.