母畑溫泉, Radioactive hot spring in Ishikawa, Fukushima, Japan

Bobata Onsen is a radioactive hot spring in Ishikawa, Fukushima Prefecture, with the highest radium content in the Tohoku region. Its alkaline simple spring water is split between Kami-no-yu and Shimo-no-yu along the Kitasu River, which flows out of Lake Bobata, and is served by six inns.

The spring was discovered roughly 900 years ago when the warrior Minamoto no Yoshiie used the water to heal wounded horses during military campaigns. This early use established a reputation for healing that later extended to human visitors.

The spring water flows through several traditional inns along the Kitasu River, where visitors bathe in the Japanese manner. Many guests come here to experience the healing properties that locals have valued for centuries.

By car, the spring is about 15 minutes from Fukushima Airport IC via the Abukuma Kogen road and prefectural routes 42 and 63, or about 40 minutes from Suku River IC on the Tohoku Expressway via routes 118, 138 and 63. Fukushima Kotsu buses between Sukagawa Station and Iwaki-Ishikawa Station stop at Bobata Motoyu, a short walk from the baths. The six inns are split between Kami-no-yu and Shimo-no-yu along the Kitasu River below Lake Bobata.

The water can be consumed directly as well as used for bathing, with a traditional practice of drinking it to address conditions like diabetes, gout, and digestive issues. This dual use sets it apart from typical hot spring facilities in the region.