Kanrei Doumon Tunnel

Kanrei Tunnel was a road facility built directly under the cliff that collapsed due to the Great Kanto Earthquake in 1931 in order to protect passing vehicles from falling rocks. As one of the first facilities in Japan built to accommodate automobile traffic, this cave gate was constructed using advanced reinforced concrete technology. As a facility symbolizing the modernization of the Hakone Road, which was a steep section of National Route 1, it holds considerable value in the history of modern roads and was designated as a National Important Cultural Property in 2015. Currently, the Kanrei Tunnel bypass has been completed, and serves as a cave bypass route for National Highway No. 1.