With a length of 6.9 km, Boryeong tunnel is also the world's 5th longest underwater tunnel. This tunnel is part of a project to build National Route 77, connecting Daecheon Port of Boryeong City to Anmyeon Island of South Korea.
This project is expected to open by the end of 2021, after that, the distance from Daecheon Beach to Anmyeon Island will be shortened from 90 minutes to about 10 minutes, contributing to boosting coastal tourism in the West of South Korea.