Introduction to Yanerdao Mountain Tunnel: Before the Olympic Games, according to the planned transportation plan, the Olympic Sailing Center needs to build a traffic road through Yanerdao Mountain. Considering that the mountain is close to the sea and the ecological environment is fragile, in order to implement the concept of "Green Olympics", Qingdao City adopted the mountain tunnel to protect the natural features of Yan'erdao Mountain, which was highly praised by the International Olympic Committee.