Mukoyama Tunnel

Overview

Mukoyama Tunnel, located in Otaki-machi, Isumi-gun, Chiba Prefecture, is a roughly 110-meter-long hand-dug tunnel. Known as a unique two-story structure, a new tunnel was dug beneath the original, creating this fascinating geological anomaly. The tunnel's interior is cool and offers a mystical atmosphere. Beyond the tunnel, the stunning scenery of Yoro-Keikoku Valley awaits. Mukoyama Tunnel was originally a simple hand-dug tunnel. However, in March 1970, road improvements were undertaken to enhance accessibility to connecting roads, resulting in a new, lower western exit. The original tunnel was not filled in, leading to this double-layered 'two-story tunnel'. While stopping inside the tunnel is prohibited, photography is possible on weekdays when traffic is light. Be sure to visit when exploring Yoro-Keikoku Valley.