Introduction to water conservancy in the Qin Dynasty: It is an artificially dug water diversion river, winding around the mountainside. The canal wall is less than two meters wide, with no end visible in the front and no side visible behind. There are steep cliffs above and below. There are cliffs several feet high, and you can hear the whistling mountain wind and rushing water from time to time. It is a veritable river in the sky, which fully embodies the wisdom of the ancient Chinese people and is breathtaking.