The Ya'erhu Ancient City is located in the Ya'er Lake Town, about 10 kilometers to the west of Turban City in the Xinjiang Uygur Autonomous Region.

Cross-embraced by two ancient riverbeds, the city got its name of cross-river city. The city was a prefecture of the Gaochang State during the Sixteen States (304-439) and the Northern Dynasty (960-1279) periods, and a county of the Gaochang Prefecture after the 14^th year (640) of the Zhenguan reign in the Tang Dynasty (618-907) and then declined. The present site of the city was built in the Tang Dynasty and the following dynasties.

Leaning on earth cliff, the city had a rectangular shape, without city walls. It was 1,000 meters long from south to north with the widest point about 300 meters from east to west. A gate was open in the east and south walls each. The most distinct feature of its construction style was that most constructions including the streets were built with the immature soil. Caves were dug out directly from the immature soil, while single-storeyed houses were built with immature soil walls and a wooden roof. Judged from pole holes left on the walls, some of the buildings were multi-storeyed houses. The lower floor was immature soil or arch-roof cave, while the upper floor walls were built with earth stamped between board frames to uphold the wooden structure. Most roofs were covered with mud and seldom with tiles.

The city was divided into three sections. A wide street stretching from south to north cut the residential area into the east part and the west part. At the north end of the street was a large-scale temple, with which as the center to form the temple area. In the south of the east part was a large well-preserved two-storeyed building, with the lower floor built underground. A flight of stairs led to the underground floor. Outside the tall walls was a large square. According to the study of the site, this temple, built in the early Tang Dynasty, was the political center of the city. Sites of workshops scattered in the west part, together with several pottery kilns. Covering an area of 5,000 square meters, the rectangular temple area comprised constructions including gate, main hall, rooms for monks, court and well.

A group of pagodas were built in the north of the city, with a big stupa in the center. The Buddhist figures on the upper part of the stupa body are illegible. The four corners each have 25 small pagodas that were arranged in 5 rows with 5 pagodas each, bringing the total number to 101.

Along both sides of the center street are tall and thick walls, with no doors open in the walls. Alleyways connected to the center street divide the city into a number of small areas. Doors can only be found along these alleyways.

Various pieces of pottery scattered in the city, most of which are decorated with gray patterns. Some of the pottery wares were made of coarse-sand red pottery and decorated with colored pattern. Scattering outside of the city are tombs that belonged to Cheshi, Gaochang and the Tang periods.

Since the city site is located in a strategic passage, so most foreign explorers who visited Chinese Xinjiang all have visited the city since the 19^th century. Chinese renowned archaeologist Huang Wenbi has conducted several excavations at the site since 1928. After the founding of new China, archaeological institutions also carried out a series of excavations here. The city has an important historical value in studying the city construction in Xinjiang.