The Dujiangyan Irrigation System, located in Sichuan province, China, is a marvel of ancient engineering. Constructed around 256 BC by the State of Qin, it is the oldest no-dam irrigation system in the world still in use, irrigating over 668,700 hectares of land. Recognized for its cultural significance and ingenuity, it was inscribed as a UNESCO World Heritage Site in 2000. This system not only controls floods but also facilitates water transport and contributes to the area's reputation as the 'Land of Abundance'.