An aerial view of the Hue Citadel in central Vietnam.
The Nguyen Dynasty (1802-1945) built four ramparts around this defensive area with 24 fortresses, each with a chamber to store matches and ammunition. Each fortress also had cannons for defense.
After the Vietnam War (1954-1975), many households began to live in this area, and many Nguyen Dynasty relics dropped out of sight.
In recent years the Thua Thien-Hue Province government has adopted a policy of relocating people from the area to enable renovations of the relics.
After a household was moved and authorities took over the site, an archway 108 cm high and 85 cm wide was discovered.
A gate built in similar style is concealed by roofs built by residents.
Nguyen Xuan Hoa, former director of the province Department of Culture and Sports, said the two gates were built for royal guards to control the entry and exit of people. The Hue Monuments Conservation Centre considers these two gates the site of the main cannons in the eastern part.
A chamber inside a fortress named Dong Vinh was found after houses in this area were demolished. The chamber walls are nearly 80 cm thick. In the past it was used to keep ammunition for the cannons, but now people use it as a storage room.
After 532 households in Thuan Loc and Tay Loc wards in the eastern side of the area moved out, many cannon holders are being seen. Cannons were the main weapons the Nguyen Dynasty used to defend the citadel.
The Tay Thanh fortress was revealed again after many households moved out. Once, this fortress was carefully guarded with many cannons around it. Nowadays it is used as farm land to grow vegetables.
A stone tablet engraved with Chinese characters. This was found after residents were relocated and the surrounding trees were removed.
The ammunition chamber is still fairly intact. It too was rediscovered after many households were moved and vegetation was cleared.
Quan Tuong, the astronomical center of the Nguyen Dynasty.
Dozens of households used to live in this area, hiding the center from sight. After they were relocated, the Hue Monuments Conservation Center carried out a renovation of Quan Tuong as well as the ammunition chamber.
Nam Thang, another fortress, has regained its original look after being renovated. Dozens of households used to live in this area for years.
Hoa, former director of the province Department of Culture and Sports, said after relocating all households in the area, the ancient architecture of Hue Citadel would be fully revealed. In future this area could become a tourist attraction if local authorities know how to exploit it, he added.