This is one of the three top hot spring spas in the valley, the other two being Hongye and Antong. Ruisui was first developed in 1919, with a public bathing area and Japanese-style hotel; and it is still in operation, with an open-air pool where visitors can enjoy a soothing soak and enjoy the fresh air at the same time.
The spring water emerges from the ground at 48 degrees Celsius and is rich in iron; the iron oxidizes upon contact with the air and gives the water a yellowish tint, causing some first-time visitors to mistakenly think that it is unclean. The water has a slightly salty (indeed, salt crystals float on its surface), rusty taste; it is the only carbonate hot spring in Taiwan.