Xian Ancient City Wall is the most complete city wall survived in China as well as one of the largest ancient military defensive systems in the world.
The wall was built in the Tang dynasty (618AD-907AD) and enlarged in the Ming dynasty (1368AD-1644AD). The construction of the Xian City was formally started in the seventh year of Emperor Hongwu reign (1374AD) and completed in the eleventh year of Hongwu reign (1378AD).
After its completion, the circumference of the city wall was 13.75 kilometers long in an oblong shape. Its height is 12 meters; its top is 12-14 meters wide and its base is 15-18 meters wide.
The military defense facilities here include the city wall, city moat, drawbridges, watchtowers, corner towers, parapet walls and gate towers once made up a complete city defense system.
The city wall includes four gates and they are respectively named as Changle in the east, Anding in the west, Yongning in the south and Anyuan in the north. The most beautifully decorated gate, the south gate Yongning, is very near to the Bell Tower in the center of the city. Each city gate has three gate towers: Zhenglou, Jianlou and Zhalou. The most outside is Zhalou, which stands away from the City Wall and is opposite to Zhenglou. It was used to raise and lower the suspension bridge. Jianlou with small windows in the front and flanks was used as a defensive outpost. Zhenglou, in the inner, is the main entrance to the city. The wall connects Jianlou and Zhenglou Towers. The area between them within the wall was called "Wong Cheng", in which the soldiers stationed. From Wong Cheng, there are sloped horse passages leading to the top of the city wall.