Dōzen Caldera

The Oki Islands emerged over six million years from two massive volcanic eruptions in the Sea of Japan. The western volcano eventually collapsed inward, forming the Dozen Caldera, which seawater later filled. Only the central cone, now called Mt. Takuhi, and the outer rim remain above water. For 30,000 years since humans settled the islands, the sheltered caldera has provided protection from the open ocean. The sacred fire maintained at Takuhi Jinja Shrine on the cone served as a navigation beacon for ships seeking the caldera's harbor, and the shrine deity came to be revered for guiding sailors safely into port.