Doan Mon historical site

The Thang Long citadel consisted of three concentric walls: the vast outer wall (La Thanh), followed by the Imperial City (Hoang Thanh), and finally the Forbidden City (Cam Thanh), the residence and workplace of the king and royal family. Doan Mon Gate was the innermost gate, leading into the Forbidden City.

The Đoan Môn Gate was originally a structure built during the Lý Dynasty, known as Ngũ Môn Lâu (Five-Gate Tower), a name still recorded in the Sùng Thiện Diên Linh stele (Đọi Pagoda) inscribed by King Lý Nhân Tông (1072-1128) in the second year of Thiên Phù Duệ Vũ (1121). However, based on the building materials and architectural style of the remaining relic, the existing Đoan Môn Gate was built by the early Lê Dynasty (15th century) and renovated during the Nguyễn Dynasty (19th century).

Doan Mon Gate holds a very important position in the ceremonial activities of the Imperial Citadel. Between Doan Mon Gate and Kinh Thien Palace is Long Tri (Dragon Courtyard, also known as Dan Tri during the Le Dynasty). This is a space of significant cultural and spiritual importance within the Forbidden City, where sacred political and religious ceremonies were held, such as the opening of the Nhan Vuong Festival (1077, 1126), the opening of the Quang Chieu Lantern Festival (1126), the review of the Imperial Guard (1351), and the King's examination for the Imperial Court (1466, 1475, 1481, 1496).

Doan Mon Gate has a U-shaped structure, measuring 46.5 meters from east to west, with 5 archways, the central archway reserved for the king.

In 1999, archaeologists chose an excavation pit right in the middle of the existing Doan Mon Gate to search for traces of the ancient Imperial Road. At a depth of 1.2 meters, they unearthed a stone border at the base of the Doan Mon Gate, a courtyard paved with large bricks from the Le Dynasty, and at a depth of 1.90 meters, they uncovered traces of a road paved with "lemon blossom" bricks from the Tran Dynasty. Running north-south, the road is predicted to extend even further and is very likely the road from Doan Mon Gate to Thien An Palace during the Tran Dynasty. Notably, among the bricks used to pave the road during the Tran Dynasty, there are also bricks from the Ly Dynasty that were reused.

Thus, the archaeological findings at Doan Mon further reinforce the hypothesis that Doan Mon during the Ly, Tran, and Le dynasties was essentially located in the same position.