City wall in ancient China was a military facility to protect the inner city from being attacked by enemies. Almost every city in China had a city wall, with the development of morden cities, most of the city walls lost their function and only a few left today. Among the existed ancient city walls, Xi'an City Wall is the best preserved and the largest in China. The construction of the city wall started in the year of 1,370 during the Ming Dynasty. The massive wall is 12 meter high, 15-18 meter wide at the base, 15 meter wide on the top, 13.7 kilometer long in circumference.
The city wall will be lit up at night and the illumistrated wall is less massive but more beautiful than in daylight.
There will be a show demonstrating the Opening Gate Ceremony of Tang Dynasty everyday at 09:30am at suspension bridge square outside of the South Gate. A Warrior Parade show will be on display at 10:30 and 16:30 everyday inside the inner city of South Gate.
There is a small museum inside the city walls at Hanguang Gate, about halfway between the southwest corner and the South Gate, accessible from the top of the city wall itself. Look for a staircase down inside a covered structure. Inside are the unrestored remains of a gatehouse from the Tang Dynasty.
Walking aroud the landscaped parks around the base of the exterior walls and moat and watching local people doing Taichi, singing local opera is also amusing. You can also enjoy a different perspective on the battlements and towers up there.