The ancient city Pingyao is in Pingyao County, Shanxi Province. The city wall was first built during the Zhou Dynasty (c.11th century-256 B.C.) and was expanded in 1370, the third year of the reign of Ming Emperor Hongwu.

The perimeter of this square city is 6.4 kilometers long and the city wall is the earliest and largest intact city wall in China. The one that stands now was built early in the Ming Dynasty and is 12 meters high with an average width of five meters Its body is rammed earth strengthened with a covering of bricks. There are crenels, a water drainage system and the top is floored with bricks. Outside the city wall there is a moat four meters wide and four meters deep. The city has six gates, twoon the east wall and two on the west and one on the south and one on the north. All the gales project outwards and have two doors each. The city has resulted in the name of "Turtle City" with the two gates on the south and north representing the head and tail of the head and tail of the turtle and four gates on the east and west as the four legs. The two doors on the south or on the north stand opposite to each other, like the head of the turtle extending out and two wells just beyond southern gate are like a turtle′s two eyes. The outer door of the north gate turns east like the tail of a turtle turned to the right. There is a tower at each gate and seven-meter-high towers at each corner. Along the wall there are platforms 50 meters apart, 3,000 crenels on the outer wall and 72 watchtowers.

The streets, old government offices, shops and residential houses inside the city retain their original styles and shapes and are a model for research on a county town seat of the Ming Dynasty. The city is under national protection. Included in the UNESCO world heritage list in 1997.

Source: http://old.cnta.gov.cn