Criterion (iv): The immense advances in science and technology achieved in ancient China are graphically illustrated by the Dujiangyan Irrigation System. IntegrityMount Qingcheng and the Dujiangyan Irrigation System have been completely preserved, with all necessary attributes demonstrating the outstanding universal value of the property included inside the property area and buffer zone. Protection and management requirementsMount Qingcheng and the Dujiangyan Irrigation System were inscribed on the World Heritage List in 2000. During the Sichuan earthquake on May 12th, 2008, Dujiangyan Irrigation System was basically undamaged, but some Taoist shrines were damaged to varying degrees. The Outstanding Universal Value of Mount Qingcheng and the Dujiangyan Irrigation System is kept through regular and rigorous maintenance and protection of the properties.