"It is difficult to get through the road, it is difficult to go to the sky." The Shimen Plane Road is built along the cliffs of the cliffs. It runs from the Hanzhong Valley in the south and goes to the Meiguan County in the north. It is one of the earliest artificial traffic tunnels in the world. Walking through the Shimen Plank Road, the mountain is steep and strange, and I have to sigh with its shock.