The Sabakoyu Onsen (鯖湖湯 or "Mackerel Lake Hot Spring") in Iizaka, Fukushima Prefecture, Japan is the oldest community onsen in the country. Sabakoyu Onsen was originally spelled 佐波来湯 when, according to legend, Yamato Takeru, prince of the Yamato dynasty and son of Keikō of Yamato, the 12th Emperor of Japan, visited the area and bathed in the hot springs. In doing so, his sickness was cured.