The Chüy Valley is a large valley located in northern Kyrgyzstan and southern Kazakhstan, in the northern part of the Tian Shan. It extends from Boom Gorge in the east to Muyunkum Desert in the west. It is 250 km (160 mi) long and has an area of about 32,000 km2 (12,000 sq mi). It borders Kyrgyz Ala-Too in the south, and Chu-Ili mountains in the north. Through the Boom Gorge in the narrow eastern part Chüy Valley is linked with Issyk-Kul Valley. The river Chu (Chüy) is the major stream of the valley.