Natsu Shirazu Cave (QR/Web)

Old tunnels running through the mountains surrounding Ginzan Onsen are remnants of the area’s silver mining heritage. The mouth of one such tunnel can be found along the nature trail through Shirogane Park. This is the Natsu Shirazu Cave (literally, “cave unaffected by summer”), so named because of the naturally cool air flowing from deep underground. The cave was once used to store ice, but these days it is most often used as a rest stop for hikers who want to cool off on a hot day.