Three Ancient Springs

The Three Ancient Springs (日本三古湯, Nihon San Kotō) are a group of ancient onsen in Japan.

According to the Nihon Shoki and Fudoki, both from the eighth century, they are:

Dōgo Onsen, Ehime Prefecture Arima Onsen, Hyōgo Prefecture Nanki-Shirahama Onsen, Wakayama Prefecture

The tenth century Engishiki gives a slightly different list:

Dōgo Onsen, Ehime Prefecture Arima Onsen, Hyōgo Prefecture Iwaki Yumoto Onsen, Fukushima Prefecture