Arimatsu Onsen Motoyu Lemon-yu is a family-run hot-spring sento founded in 1986, known for jet-black natural moor water from 800 m underground. Its loyly sauna runs very hot, 120-130°C on the men's side and around 100°C on the women's, with weekly changing aromas; cooling is a groundwater cold bath and an open-air plunge pool. Entry 500 yen plus 200 yen for the sauna; two private family baths have their own sauna. Open 9:00 to 23:00, closed Mondays.
