Introduction to Dongtian River: Dongtian River is named after the long-running underground river rushing out from the cracks in the rocks. The sound of the water is shocking to the eardrums. There are white translucent and crystal alabaster, botryoidal stone flowers and coral stones on the cave wall here, which are extremely precious. There are wonderful sights in the cave - a horizontal pool that neither rises nor falls and the "Dinghai Shenzhen" and other landscapes.