Introduction to the underground river in the cave: The underground river in Fengyu Cave is 3.3 kilometers long. This underground river is currently the most fully developed and utilized underground river in the world. The landscapes on both sides of the underground river are lifelike (this is one of the scenes in the underground river, "Jiang Taigong Fishing"). The entire journey of the underground river is done by manual rowing. The Underground River Tour is full of mystery, temptation, and excitement. The Underground River Tour is very ornamental.