Saekhyeon Tunnel (색현터널)

Saekhyeon Tunnel, spanning 423 meters in length, was first opened in 1939 and functioned as part of the Gyeongchun Line railway up until 2010. After the railway line was rerouted, the tunnel found a new purpose as a section of the Bukhangang Bike Path. It has also earned the nickname "Moss Tunnel" due to the moss that has grown around its entrances. The tunnel, especially known for its distinctive round entrances, has become a favored location for photography enthusiasts.