Tsutenkyo is a giant bridge-shaped rock protruding into the sea. Caves and cliffs of rough basalt eroded by the sea span about seven kilometers along the Kuniga Kaigan Coast, the largest scenic spot in the Oki Islands and designated as part of the Daisen-Oki National Park. Tsutenkyo was created by volcanic activity over five million years ago, and the central area of the stone shape has been hollowed out by marine erosion, creating its arch-like shape. Even today, the rock continues to erode. Stop by and visit to see this unusual phenomenon created by nature.