The Ancient Karez system is comprised of a series of wells and linking underground channels that uses gravity to bring ground water to the surface, usually far from the source. It is the crystallization of ancient people´s diligence and intelligence.

In Turpan city there are more than 470 systems, totaling over 1,600 kilometers of tunnels. It is considered as one of the three great projects in China with the other two being the Great Wall and the Grand Canal.

The history of Karez can be traced back to the Han dynasty. Most of karezes existing today in the Turpan were built in the Qing dynasty.

The water source of the karez is melting snow from the Tianshan Mountain. Water is collected by vertical wells and conducted by the underground canals to the oasis, where the water is held in the ground canals for irrigation. The vertical wells near the water source may be 100 meters (328 feet) deep while further downstream they are less than 10 meters (32.8 feet) deep.

Also Karez systems functions as the natural air conditioner for the locals. They can sit in one while chatting or doing some chores.