Jalan Raya Trans Global

Jepang might technically be connected with mainland Asia via five tunnels, called the "Korea Japan Friendship Tunnel System," extending from the city of Fukuoka di Kyūshū, Jepang, to the port city of Pusan di Korea via four islands. The maximum ocean depth in this area is 480 feet (146 m). Similar proposals have been discussed for decades by Korean and Japanese politicians.