Central Sector of the Imperial Citadel of Thang Long - Hanoi

The Thang Long Imperial Citadel was built in the 11th century by the Ly dynasty, marking the independence of Dai Viet, on the remains of a 7th-century Chinese fortress on land drained from the Red River delta. UNESCO says it was the centre of regional political power for almost 13 centuries without interruption, and that the buildings and the remains at the 18 Hoang Dieu archaeological site reflect a culture specific to the lower Red River valley, between China to the north and Champa to the south.

Construction began in 1010 under Emperor Ly Thai To and was completed in early 1011. Most of what stands dates from Gia Long's rebuilding of 1805, and the French demolished much of the citadel for offices and barracks, leaving the North Gate and the Flag Tower. Hanoi has been a capital for more than a thousand years, through several invasions and name changes.

More on the UNESCO listing More on Wikipedia