Introduction to Longtan: Going to the right branch of the cave is the mouth of Longtan. It is deep and dark. The diameter of the cave gradually narrows and twists and turns. You can only crawl forward in the extremely narrow place. Two huge rocks stand on the left and right sides of Tankou, the left one looks like a roaring lion. The eyes are wide open, and the one on the right side looks like Zen Hate with crane hair, holding his beard in his hand, and smiling broadly. The way to Longtan from here is to pass through "thousands of rivers and mountains". The two corridors are full of rugged rocks and rare animals with inexplicable shapes, close to the dragon pool, and their roaring sound is like thunder piercing the ears, looking up. I saw a stream of water pouring down from the stone wall like a jade pillar, rushing straight into Longtan, rolling up thousands of waves, which was magnificent and magnificent.