The Imperial Citadel of Thang Long, also known as Hanoi Citadel, was built in the 11th century by the Ly Viet Dynasty, marking the independence of the Dai Viet. It was constructed on the remains of a Chinese fortress dating from the 7th century on drained land reclaimed from the Red River Delta in Hanoi. It was the center of regional political power for almost 13 centuries without interruption.
Witness the remains belong to the 9th century, the Chinese culture and architecture,