🧿 Tonkararin Tunnel Structure

The Tonkararin or Tonkararin tunnel structure is a 464.6 m (1,524 ft) long, tunnel-like structure of unknown origin, situated in Nagomi, Kumamoto Prefecture, Japan. It lies on a plateau called Seibaru Daichi, around which are many kofun or tumuli, such as Eda-Funayama Kofun. It consists of very shallow natural slits of the ground covered with stones and man-made stone-structured underdrains. The name of Tonkararin came from the sound of a stone, when the stone is thrown into the tunnel. Another view is that it came from the Korean language. Korean Tongurami, similar to Tonkararin was a cave connected with religious functions.