Nestled between Yulei Mountain and Lidui in China's Sichuan Province, Baopingkou stands as a testament to human ingenuity. This 2,200-year-old sluice gate—part of the UNESCO-listed Dujiangyan Irrigation System—continues to awe engineers and historians alike with its timeless functionality.
Constructed during the Qin Dynasty by visionary engineer Li Bing, the 40-meter-long structure showcases ancient innovation. Workers used fire and water to carve through solid rock, creating a bottle-neck channel that automatically regulates water flow from the Minjiang River. The system's seasonal width adjustments (19-23 meters) and partnership with Feisha Weir demonstrate an early understanding of centrifugal force, diverting 75% of sediment while preventing floods and droughts.
What makes this 'treasured bottle mouth' truly remarkable is its enduring legacy. The system still protects the Chengdu Plain today, supporting agriculture for millions while maintaining ecological balance—a blueprint for sustainable water management that modern engineers still study.
