This relic of an ancient urban area and military citadel is located in Co Loa Village, Dong Anh District, Hanoi. Throughout history, Co Loa was nominated twice as the capital of Vietnam: the first time during the An Duong Vuong era in the late 3rd and early 2nd century BC, and the second time during the Ngo Vuong Quyen reign in the middle of the 10th century. The three ramparts archeological relics from the Bronze and Iron ages are 16km long. The complex of religious and commemorative relics includes Ngu Trieu Di Qui Communal House, My Chau Temple, and Bao Son Pagoda. Mystical relics such as Ngoc Well, Flag Tower, and Ngu Xa Castle make of this area a culturally and historically interesting area.