The Guanziling Hot Springs (關子嶺) are located in the foothills of the mountains of Taiwan, about 70 km northeast of Tainan City. These hot springs produce a fine, silty mud which is found in only three places in the world. It's said to be magnificent for the skin. Whether it is, I do not know, but it feels pretty amazing. The springs are quite inexpensive, and are in a beautiful area with lots of nearby walking and hiking paths. It is also very close to the burning water.