Located in the cliffs more than 100 meters north by east of the Dragon VAT, it is the first karst cave of the Dragon VAT. The tunnel is 43 meters long, with a strike of 250 to the northeast, and the South portal is 3.9 meters high and 3.4 meters in diameter; The North portal is 2.4m high, and the north end is the outlet of the underground river. Every year on the night of the Mid Autumn Festival, the moon rises from the East and fills the whole cave. The cluster of silver light shines through the cave from north to south like a flashlight. People call this strange landscape "reflecting the moon through the cave".