The City Wall is the best-preserved one of all the ancient city architectures in China; it is also the most integrated and the largest city wall in the world. It was built on the ruins of the imperial city of the Tang Dynasty for defense and keeping reserves, so it was very firm.
The city wall is 12 meters in height. It is 12—14 meters wide across the top, 15-18 meters thick at the bottom and 13.7 kilometers in length.

There is a rampart ever 120meters apart, which extends out from the main wall. The ramparts were built to allow soldiers to see those enemies who would try to climb the wall. The distance between every two ramparts is just within the range of arrow shot from either side. There are altogether 98 of them on the wall; each has a sentry building on top of it.
Each of the east (Changle, long happiness), west (An' ding, peace), north (An' Yuan) ,south (Yongning) gates consists of three gate towers. The main gate tower is called zhenglou with a suspension bridge. And jianlou is the arrow tower which is used to lift and lower the suspension bridge. There are square windows in the front and on the two sides to shoot arrows from. The zhenglou is the inner one and is also the main entrance to the city. Jianlou and zhenglou are connected by walls and the encircled area is called the wongcheng in which soldiers could be stationed. From wongcheng, there are also eleven horse passages leading to the top of the wall.

A watch tower is located on each of the four corners of the wall. Along the outer crest of the city wall, there are 5,984 crenellations or battlements. Under each crenel there is a square hole, from which arrows were shot and watch was kept. The lower inner wall on the top of the wall is called parapets which were designed to prevent soldiers from falling off the wall when they were traveling on its top.

The city wall was first built as earth, rammed layer upon layer. The base layer was made of earth, quicklime, and glutinous rice extract, tempered together. Then it was totally coated with bricks. So it was very firm. A wide and deep moat runs around the city. Over the moat, there used to be a suspension bridge which was the only entrance to the city.
Today , in order to protect the old city wall, the government repaired the moat and built a circular park along the high wall and deep moat. The big South Gate Square at the end of the South Street was also built. In 1998, the American President Bill Clinton visited Xi'an. The city government held red-carpet entrance ceremony there. Clinton received the gate key then entered into the ancient city.

Every year, on the Festival of Lanterns (lunar calendar 15th January) and Xi'an Cultural and Artist Festival (October), lantern exhibition will be held on the city wall. At that time, if you travel on the city wall, you will find that the lanterns are all bright and the city night is so beautiful. If you are in Xian, please don't lose the chance to experience the most graceful Xi'an.