This is the largest city ruins in west China. The site is located 40 kilometers from the Turpan City, at the north bank of the Aiding Lake and to the south of the Flaming Mountain. It was listed as the National key cultural unit in 1961.

Gaochang(高昌Gāochāng) was an ancient city with a history of more than 1300 years and it was destroyed in the war. The city saw frequent changes of dynasties in hundreds of years.

It was once a fertile and cultivated land and served as capital of three western states. From the historical documents and relics excavated in the region, historians are able to sketch the outline of this grand city. Gaochang's ideal location at the middle of the Turpan Depression and the city's well layout with high walls and deep moats made it a significant military fortress of the Western Region over years.

The ruins cover around 2.2 million square meters, containing the outer and inner cities. The layout of the city is similar to that of Chang'an, capital of Tang Dynasty at that time. The outer wall is the only visible structure left now.