Karez Irrigation System
The Karez is an underground irrigation system that
was constructed over 2,000 years ago and is considered 1 of the
greatest engineering achievements of ancient China, with the Great
Wall and the Grand Canal.
It is a series of wells and underground channels
that transferred water, usually from the glaciers on the base of
the Tian Shan, to communities in the area. Many cities on the ancient
Silk Road, some as far west as modern Iran, relied on this irrigation
system as a primary supply of water.