Tianmen introduction: Tianmen cliffs stand on both sides of the trail, forming a natural stone gate, which can be called a natural fortress. Standing here and looking up and down, you feel like you are between the mortal world and the heavenly palace; looking down, you can see the roaring Xiangzi River, layers of rice fields, and the curling smoke of cooking stoves. The beautiful scenery of the human world is integrated with the fantasy of heaven.