The ruins of the ancient city of Guyuan, Ningxia

The ancient city of Guyuan is divided into the inner city and the outer city, with a flat shape of 'Hui'. The inner city was built in the third year of Emperor Wu of Han Yuan Ding (114 BC), and was rebuilt many times in the Eastern Han, Northern Zhou, Sui and Tang dynasties. It is nine miles and three minutes in circumference, three feet and five feet high, three feet and eight feet wide at the bottom, and two feet and two feet wide at the top; in the fifteenth year of Ming Hongzhi (1502), the outer city was added, with a circumference of thirteen miles and seven minutes, three feet and six feet high, four feet wide at the bottom, and two feet and three feet wide at the top. In the third year of Ming Wanli (1575), the outer city of Guyuan Prefecture was protected with bricks and stones, and corner towers, artillery platforms, driveways and crenellated walls were added, with ten city gates, three of which were in the east, the famous ones being Anbian and Baoning; four in the south, the famous ones being Zhenqin and Xingde; two in the west, the famous one being Weiyuan; and one in the north, named Jingshuo. In the 1920 Haiyuan earthquake, the city walls and towers were severely damaged. In the 1970s, part of the city wall was demolished, and now 15 sections of the inner and outer city walls are preserved, with a length of more than 2,400 meters. On March 5, 2013, it was announced by the State Council as a national key cultural relics protection unit.