The state bordered Kucha and thence Aksu to the west, and Korla and Turfan to the east. To the south, across the desert, was Khotan.
References
Hill, John E. The Western Regions according to the Hou Hanshu (http://depts.washington.edu/uwch/silkroad/texts/hhshu/hou_han_shu.html), Second Edition, 2003.
Puri, B. N. Buddhism in Central Asia, Motilal Banarsidass Publishers Private Limited, Delhi, 1987. (2000 reprint)
Korla (simplified Chinese: 24211;尔勒; pinyin: Kù'ěrlè) is a city south of Karashahr (Yanqi), and is the capital of the Bayinguoleng Mongolian Prefecture, the largest prefecture in China.
Korla has long been the biggest centre in the region after Karashahr itself, having abundant water and extensive farmlands, as well as controlling the main routes to the south and west of Karashahr.
The Iron Gate Pass (Tiemenguan) leading to Karashahr is about 7 km (4 miles) north of the city and, as it was easily defended, played an important part in protecting the ancient Silk Roads from raiding nomads from the north.