The Imperial Citadel of Thăng Long is a complex of historic buildings associated with the history of Vietnam located in the centre of Hanoi, Vietnam. Its construction began in 1010 and was completed in early 1011 under the reign of Emperor Lý Thái Tổ of the Lý dynasty. Most of the existing structure is dated to the extensive reconstruction of the old Imperial Citadel ordered by Gia Long in 1805, but the Citadel was largely demolished by the French to allow more land for offices and barracks.