A public bathhouse in one of Kyushu's oldest hot spring areas, boasting approximately 1,300 years of history in Chikushino City, Fukuoka Prefecture. Futsukaichi Onsen first appears in history during the Nara period, recorded in Japan's oldest poetry anthology 'Manyoshu,' where Otomo no Tabito, the head of Dazaifu, composed a poem mourning his late wife. The 'Suita no Yu' mentioned in the poem is today's Futsukaichi Onsen. Known historically as 'Suita no Yu,' 'Yakushi Onsen,' and later 'Musashi Onsen,' it had a hot spring administrator appointed by the Chikuzen domain during the Edo period, with an exclusive 'Gozenyu' bath for Lord Kuroda. Hakatayu was established in 1860 (Manen 1) and features a distinctive three-story wooden building that retains its original atmosphere. The water quality is simple hot spring (weakly alkaline, hypotonic, high-temperature spring), with 100% free-flowing source water from 260 meters underground. This rare radioactive spring is heated by uranium in the 90-million-year-old Sawara granite distributed throughout the Chikushino area, transforming into radium and radon. The radon-rich water has a pleasant sulfur scent and is renowned as a 'Beautiful Skin Hot Spring.' The semi-underground bathhouse features cloudy source water for pouring over yourself, allowing guests to enjoy fresh hot spring water. Selected as Number 1 of the Kyushu 88 Hot Springs.