Constructed between 1805 and 1832 on the north bank of the Hương (Perfume) River according to Vauban principles of fortification and the doctrines of ancient geomancy, Huế Citadel was the royal capital of Nguyễn dynasty Việt Nam. Surrounded by a moat, the 21 metre-thick ramparts incorporate 10 entrance gates. A majestic flag tower stands in front of the citadel. The focal point of the citadel’s 520-hectare interior is the Royal Enclosure (Hoàng thành), which is enclosed by a 4 metre-high stuccoed brick wall and surrounded by a canal. The Royal Enclosure incorporates the Forbidden Purple City (Tử Cấm thành), which has four gates, the most imposing being the South Gate (Ngọ môn), considered today to be a masterpiece of Nguyễn architecture, which was traditionally used for ceremonies involving the king and his senior officials. Regrettably many of the royal palaces within the Forbidden Purple City fell into disrepair long before the Tết Offensive of 1968, when the monuments became the backdrop for one of the most bitter battles of the Second Indochina War. By 1975 only 20 out of the original 148 buildings were left standing. Since 1996 significant progress has been made in restoring the remaining monuments.

Related links: Huế Historic Monuments.