Tianmen Cave is the highest natural karst cave in the world. In the six years of Wu Yongan (263 A.D.), the cliffs of Songliang Mountain burst open, and Wu King regarded it as auspicious. It was also renamed Tianmen Mountain and placed Tianmen County below. Tianmen Cave crosses north and south. It is 131.5 meters high, 57 meters wide and 60 meters deep. It is like a gateway to the sky. This scenic spot has attracted many emperors, officials, hermits, monks and monks, scholars and ink travelers from past dynasties to visit and visit, and has accumulated for generations, forming a unique and thick "astronomical" Tianmen Mountain. The "Tianmen Smoke", "Tianmen Xiaguang" has been praised as a rare spectacle in the world.