Overpass introduction: There is a deep gorge more than 100 meters deep in the west of Tianzhu Guan. In the narrow part of the gorge, there is a simple stone bridge more than ten feet long and one meter wide. It is called "Overpass". The stone bridge is If it is broken, it is a natural chasm. About 30 meters west of the overpass is the second pass - Xifeng Gate, which is also built against the wall due to natural dangers. To the east of Tianzhu Guan is a cliff, on which a zigzag earthworm trail is forged by stonework, which is the only way for people to go up and down the mountain. Thinking back to those days, people set up such a dangerous and majestic pass among the lofty mountains, which shows the importance of its strategic position and the fierceness of the war. From the Tianqiao to Tianzhu Pass, there are seven inscriptions on the stone wall. The earliest one was inscribed in the second year of Chongning (1102) by Emperor Huizong of the Song Dynasty. It has been more than 900 years ago. As you can imagine, Tianzhu Regarding the importance of ancient military status.