Funsenchi

Free outdoor hot spring bath right beside the Hida River in Gero, and unlike most onsens it is mixed-gender and open to the sky, so bathers wear swimsuits. Smooth river rocks line the pool, which receives a steady flow of hot water around the clock, pausing only for a morning cleaning. The sound of the river and views of the surrounding mountains make it pleasant at any hour, but visiting at night, when inn lights glow along the hillsides and the sky fills with stars, is particularly worthwhile. It sits conveniently between Gero Station and the hot spring district.