On the edges of Guan County is Dujiangyan, one of China's earliest irrigation systems. Begun over 2,200 yearsago 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 with modern equipment instead of stones and bamboo.

The best place to see the system is at Fulong Temple, built in AD 168 during the Han dynasty in honor of Li Bing and his son. The Guanlan Bridge is the highest point in the temple complex and overlooks the river. In the buildings are artifacts related to Li Bing and in the main hall is a 3m tall, 4.5-ton statue of him that was thrown into the river as a sacrifice.