Introduction to Tingjiangyuan Longmen: The Longmen Cave is high and open, with strange rocks standing on the wall. The cracks in the cave wall bend and stretch upward, like a dragon's body entrenched, creating a wonderful scene. Inside and outside the cave door is a deep pool, which is too deep to sideways. Hitting the stone pool, there was a sonorous sound. Whenever there is a flash flood in spring, the rapids echo and rumble, and the river roars out of the cave, which is a spectacular sight.