[1] The fall of the Tang dynasty brought about a period of turbulent independence in Vietnam called the Anarchy of the 12 Warlords, which ended after the creation of the Đại Việt monarchy.

The material remains of the original structure are limited to the foundations of the complex (mostly made from terracotta), an extensive drainage system, and various royal architectural decorations.

Associated with the common view of the Lý dynasty as a Vietnamese "golden age"[3] the archeological remains have deep significance to the national history of Vietnam.

Lê Thái Tổ ordered repairs to the citadel after the damage caused left by the war with the Ming army.

When it was controlled by the French as the capital of Indochina (1885–1954), the Citadel of Hanoi was largely demolished to make the land for offices and barracks.

Except for the North Gate and the Flag Tower, what remains of Hanoi citadel to this day is only an archaeological site and restored.

[4]: 19–20 During the Vietnam War, the Imperial Citadel was used as an administrative capital and headquarters for the North Vietnamese Ministry of Defense and Army.

In 2004, the Ministry of Defense moved from the Central Sector of the site so that the relics could be more completely conserved by the Hanoi People's Committee Department of Culture and Information.

Architectural and foundational remains of the Imperial City were discovered on the site of the former Ba Đình Hall at 18 Hoàng Diệu Street when the structure was torn down in 2008 to make way for a new parliament building.

[2][10] The Ancient Citadel is constructed on a slightly offset north–south axis and organized according to traditional geomantic principles (phong thuy; feng shui) which give the site a historic and spiritual significance.

[2] Because natural ground has a poor load-bearing capacity, the architectural scale and complexity is considered a significant technical advancement of the Vietnamese in construction.

Along with important discoveries of architectural vestiges, a large number of ceramics, which were used in daily life in the Royal Palace through many periods, were also found.

[2][14] Among the structures related to the Imperial City is the Hanoi Flag Tower (Cột cờ Hà Nội).

[2] Đoan Môn is the archway leading to Kinh Thiên throne hall and the primary (southernmost) entrance to the Forbidden City.

In 2002, Vietnamese archaeologists, who were allowed to dig in the area, found the "ancient carriageway" of the Trần dynasty, using many Lý bricks, the study of which is still ongoing.

[2] The front, south entrance of Kinh Thiên Palace platform features a large staircase consisting of 10 steps divided into three equal parts (used similarly to the gates of the Đoan Môn, with the central staircase reserved for the emperor and the others reserved for the royal family and officials) by two large dragon statues, constituting what are called the "Dragon Steps".

It was built the contemporary architectural style (to look like a house and hide its military significance) with many defensive features, including a 60-centimeter thick soundproofing wall, reinforced entrances, and a connecting tunnel that allowed for emergency evacuation in case of an attack.

[2] The building currently serves as a museum which exhibits tools that comrades in the Politburo and the Central Military Commission, the Ministry of Defense and the General Staff used in the Vietnam War.