The ruins of Karakhoja or Gaochang Gucheng (Gaochang Ancient City) date from the initial Han Chinese conquest of the area in the 2nd century BCE.

Located about 46km southeast of Turpan on the edge of the Lop Desert; Karakhoja is larger than Yarkhoto; but rather less well preserved. Originally established as a garrison town; it developed into a prosperous city by Tang times; before being eventually abandoned in the 14th century; probably due to a combination of endemic warfare and desertification. In its prime; Karakhoja was divided into three sections - an outer city; inner city; and palace area.