One of the symbols of Nagayu Hot Spring Town, this is a hot spring that has the legend of a crab that fell in love with a human girl. This place is a mixed-gender outdoor bath along the river, surrounded by an open nature. Guests can undress at the dressing room under the bridge and enter the bath. Although you need a little courage to enter the bath naked, women are allowed to wear swimsuits. Although this place is open 24 hours, it does not have any facilities, such as towels, so please prepare in advance if you plan to take a bath here.