Kiyotsu Gorge

One of Japan's largest gorges, Kiyotsu stretches 12.5 kilometers through Niigata and displays unusually clear examples of both horizontal and vertical columnar jointing, the angular rock formations created as ancient magma cooled. A pedestrian tunnel completed in 1996 provides access after the original riverside path was closed for safety in 1988. In 2018, architecture firm MAD Architects transformed the tunnel as part of the Echigo-Tsumari Art Triennale, creating the Tunnel of Light installation: a stainless-steel chamber at the end of the path, its floor flooded with spring water that mirrors the gorge above. The tunnel is generally closed from mid-January through February.