Dien Hai Citadel is located on the left bank of the Song Han River, built in 1813 during the Gia Long reign, initially named Bao Dien Hai, constructed of earth. Due to its proximity to the sea, it was easily damaged. In 1823, King Minh Mang ordered it to be moved into the inner city and rebuilt with bricks on a high mound, following European Vauban architecture, creating a solid defensive fortress. The citadel has a perimeter of 556m, walls over 5m high, surrounded by a 3m deep moat. The main gate faces South and the auxiliary gate faces East. Inside, there is a royal palace, a flagpole tower, granaries, ammunition depots, gunpowder storage, and it was equipped with 30 large artillery gun emplacements. During the resistance against the French-Spanish allied forces (1858-1860), the citadel played an important role in defending Da Nang, demonstrating the courageous fighting spirit of the Vietnamese people. Today, the citadel has been restored and preserved, becoming a special national historical site, attracting tourists to visit and learn about the glorious history of the nation.
