Banpo is an archaeological site discovered in 1953 and located in the Yellow River Valley just east of Xi'an, China. It contains the remains of several well organized Neolithic settlements, like Jiangzhai, carbon dated to 6700–5600 years ago. The area of 5 to 6 hectares (12 to 15 acres) is surrounded by a ditch, probably a defensive moat, 5 to 6 meters (16 to 20 ft) wide. The houses were circular, built of mud and wood with overhanging thatched roofs. They sat on low foundations. There appear to be communal burial areas.