The Dahan Stronghold, situated along the Tieban Coast to the south of Nangan, is a major historical site located near the Nangan Tourist Service Center. Together with the fortifications at Juguang Island, 33, and 46, this stronghold created a tightly secured network controlling the Tieban and Meishi Anchorages, effectively sealing the straits toward Juguang. Strategically vital, the stronghold was constructed in 1975 to fulfill operational military needs. At that time, soldiers of the amphibious infantry unit worked relentlessly around the clock under crude conditions. With limited equipment, the construction relied on manpower to excavate terrain bit by bit, in addition to controlled explosive demolition. The fortifications were completed on March 29, 1976. The stronghold features three levels. The top level housed the military command center, while the second level included living quarters and an auxiliary machine-gun position. The lowest level consisted of four 90mm anti-aircraft gun emplacements, briefing rooms, conference facilities, storage rooms, and supply warehouses. The tunnels have a width of approximately 1.5 meters and a height of 2 meters. The main tunnel extends 150 meters, and connecting tunnels add another 80 meters, totaling 230 meters. With the easing of military tensions, the stronghold transitioned to the Matsu National Scenic Area Administration in 2006 for further development and preservation as a cultural and touristic asset. Inside the bunkers, every gun aperture and cannon points directly toward the ocean, exuding a solemn and battle-ready atmosphere. It vividly reflects the military spirit of the past, as summarized in the slogan "Guarding the Sea Area and Demonstrating the Might of the Chinese Nation." Tourists can access the site by following the path near the Nangan Tourist Service Center; circling beyond the upper area of the stronghold on a clear day provides a clear and distinct view of the outline of Juguang Island.