The Zhaishan Tunnel are located to the southeast of Gugang Lake, in an area where the southern coastline juts out. Construction began on these tunnels in 1961 and was completed on March 22, 1966.

The Zhaishan Tunnel stretch over a distance of 101 meters, with a width of 6 meters and height of about 3.5 meters. Inside are seven rooms that served as barracks. A unique feature of these tunnels is the A-shaped waterways. These waterways have a length of 357 meters, a width of about 11.5 meters and a height of about 8 meters, and were used to conceal small naval vessels.