Lishui Tongjixuan, located in the Bihu Plain in southern Zhejiang Province, a small village called Shantou, was built in the southern dynasty Xiaoliang Tianjian four years (505 AD), has a history of more than 1,500 years. Tongjixuan is the oldest large-scale water conservancy project in China, and the world's earliest arch dam, composed of water dam, inlet gate, three-hole bridge, channel and leaf hole, is a precious data for studying ancient water conservancy projects in China, and is a key national cultural relics protection unit.