showed evidence of a walled city founded 1,600 BCE. The trapezoidal city has an east wall 2,000 m, south wall 2,000 m, west wall 1,600 m enclosing 3.6 km2, similar in scale to the inner city of the Zhengzhou Shang City. The city was built on the banks of the Yazi River (), and enclosed part of its tributary, Mamu River, within the city walls. The city walls were 40 m at the base and 20 m at the top, varying in height from 8–10 m. There was a smaller set of inner walls. The walls were surrounded by canals 25–20 m wide and 2–3 m deep. These canals were used for irrigation, inland navigation, defense, and flood control. The city was divided into residential, industrial, and religious districts organized around a dominant central axis. It is along this axis that most of the pit burial have been found on four terraces. The structures were timber framed adobe rectangular halls. The largest was a meeting hall about . Discovery Evidence of an ancient culture in this region was first found in 1927 when a well-to-do farmer unearthed a large stash of jade relics while dredging an irrigation ditch, many of which through the years found their way into the hands of private collectors. In 1931, the discovery was brought to the attention of Vyvyan Donnithorne, an Anglican missionary stationed at the Gospel Church of Guanghan. He recognised the importance of the discovery and contacted a local magistrate as well as Daniel Sheets Dye, a professor of geology at West China Union University (WCUU). The three of them then visited the location and photographed and measured the site. Through the magistrate, a few items were acquired and sent to the museum at WCUU. Then, in 1934, David Crockett Graham, the new director of the museum at WCUU, organised the first archaeological excavation of the site. In 1986, local workers accidentally found sacrificial pits containing thousands of gold, bronze, jade, and pottery artifacts that had been broken (perhaps ritually disfigured), burned, and carefully buried. Containing approximately 800 objects, the second sacrificial pit was found a little less than a month later, on August 14, 1986, only 20–30 meters from the first one. Bronze objects found in the second sacrificial pit included sculptures of humans, animal-faced sculptures, bells, decorative animals such as dragons, snakes, chicks, and birds, and axes. Tables, masks, and belts