FILE PHOTO: Remains of supporting pillars under the Romanesque bath at Tangchaodun site

The site of Tangchaodun is located in northeast Qitai County, near the eastern section of the Tianshan Mountains. Residents of Qitai County have long been aware of the existence of this abandoned ancient city, but knew little about it. In recent years, a large number of cultural relics from the Tang Dynasty (618–907) have been discovered in this ancient city site. The name of this site, Tangchaodun, literally known as Tang Dynasty mound, was derived from the presence of a rammed-earth platform on its northern city wall.

Archaeological excavations and carbon-14 dating results indicate that Tangchaodun was first built in the early Tang Dynasty, which is roughly consistent with the date when Pulei County was founded—the year 640—recorded in archives. During the period of the Qocho Kingdom (866–13th century), the city walls were re-rammed and strengthened. From the Yuan Dynasty (1271–1368) onward, the city site had been basically abandoned.