Thang Long – Hanoi Imperial Citadel (Vietnamese: Hoang thanh Thang Long) refers to a cultural complex located in the heart of modern-day Hanoi, and its traces were recently uncovered during construction of new buildings in 2002. The site at 18 Hoang Dieu Street, was chosen for the construction of the National Assembly, but development stopped when traces of the Imperial Citadel were uncovered. It was inscribed as a cultural heritage site by UNESCO in 2010. Originally, the Imperial Citadel was first built in the 11th century by the Ly Dynasty, marking the independence of the Dai Viet kingdom after a millennium of Chinese colonial rule.
It was constructed on the remains of a Chinese fortress on drained land reclaimed from the Red River Delta in Hanoi. The site would remain the center of uninterrupted regional political power for the next several centuries. The Citadel enclosed the Forbidden City, constructed in brick in the 11thcentury, and was itself enclosed by a defensive wall.
The Citadel reached its apogee in size in the 16th- 17th centuries. French colonial control of Vietnam began in the 1880s, and Thang Long functioned as the colonial headquarters for French administration of Indochina (modern Vietnam, Laos, and Cambodia). Due to its historical significance and location within the modern capital of Vietnam, the management of the site is quite complex and has increasingly involved multinational participation.
Another cultural heritage: Ho Dynasty Citadel – a cultural heritage