Dujiangyan Irrigation System
The Dujiangyan Irrigation System is situated about 50 km from Chengdu, on the edges of Guan County and is one of China's earliest irrigation systems. Created over 2,200 years ago by Li Bing and his son, the system irrigates the area around the Minjiang River and has been continually expanded. It's still in use today, though modern equipment is used rather than the previously used stones and bamboo.
The best place to see the system is at Fulong Temple, built in AD 168 during the Han dynasty in honour of Li Bing and his son. The Guanlan Bridge is the highest point in the temple complex and overlooks the river. In the building, artifacts related to Li Bing are on display and in the main hall is a 3m tall, 4.5-ton statue of him that was previously thrown into the river as a sacrifice.