This 300 meter tunnel was built in 1972 beside the NCO training camp. The Andong Tunnel cuts right through the Erchong Mountain—a truly magnificent military construction that was designed as an operational tunnel. Upon entering the tunnel, you will have to walk downward at a 30-degree angle. In the tunnel, you will find 8 outlook holes—these used to be cannon holes that allowed the army to oversee and control all military action from high vantage point.

The tunnel is equipped with all sorts of military facilities, including the troop’s sleeping quarters, toilets, wells, arsenal, meeting rooms, and even a pigsty. It’s hard to imagine how the soldiers who were stationed here managed to complete such a massive underground construction.

Every year, between spring and summer, colonies of black-tailed gulls gather on the cliffs along the coastline, just outside of this tunnel. The birds come to mate and search for food. It’s a very rare ecological experience to be able to observe these birds at such a close distance.