Dujiangyan (Dujiang Weir), located west of Dujiangyan City, Sichuan Province, was built and is still in use in ancient China's large-scale water, known as "the originator of the world's water conservation culture" is a famous tourist destination in Sichuan. Generally accepted that the Dujiangyan Irrigation Project is Qin Shujun Li Bing and its sub-prefect to mobilize people to build in the first 256 years or so, is by far, the world's oldest, only retention, diversion dam is characterized by ambitious water project, is national key cultural relics protection units.