Dujiangyan Irrigation System, Dujiang Weir, is located west of Dujiangyan City, Sichuan Province. Originally it was called Du’an Weir after the name of the ancient Du'an County, where the weir was situated. Since Song and Yuan dynasties its was given the present name Dujiang Weir, honored as the "Guarding Treasure of Sichuan Province" that is "ingenious of all times".
The irrigation system was constructed in 227 BC by Li Bing, governor of Shu Prefecture, over 2,200 years ago. It is not only the earliest water control project in China, but also the only and the oldest remain of its kind in the world. Characterized in its successful control of water without only blocking dam, Dujiangyan Irrigation System is a milestone in the history of technology in China.
In December of 2000, Dujiangyan Irrigation System was inscribed by UNESCO in World Heritage List as cultural heritages of the human world.