Genzan Cave

Genzan Cave formed when groundwater slowly dissolved calcium carbonate deposits deep underground. The cave once ran about 2 kilometers until a 1659 earthquake collapsed most of it, reducing it to around 50 meters. Fossils of marine life found inside confirm that the area once sat beneath an ancient caldera lake. According to legend, the warrior Minamoto no Aritsuna hid here while fleeing rivals during the Genpei War. He was discovered not by sound or sight but by starchy white residue from rice he had washed in the cave's waterfall, which drifted visibly downstream. The cave is easily reached on foot from a nearby parking area.