Dujiangyan is not a ruin that survives only in a museum label. Built on the Min River in Sichuan around 256 BCE, it remains part of a working water-management system serving the Chengdu Plain. UNESCO describes the design as an ecological engineering achievement: instead of blocking the river with a conventional dam, it uses the natural slope and flow of water to divert irrigation supplies, pass sediment and reduce flood risk. Its long life comes not from being frozen in its original form, but from repeated repair and adaptation over more than two millennia.
The World Heritage property combines the irrigation works with Mount Qingcheng, a separate Taoist sacred mountain to the south. They were inscribed together in 2000, but they are distinct experiences and have separate visitor arrangements. The irrigation system is the place for reading how water is divided and controlled; Qingcheng is known for temples and religious history. Keeping the distinction clear helps travelers choose their route and avoid assuming that one ticket or one short visit covers both landscapes.