Before I went to Yixing, I also swam underground river once, but I felt totally different. The small entrance of Chuiyun Tongtian River and the twists and turns in the cave are the contrast of regression. Before entering the cave, the feeling before entering the cave is totally different from that before the cave, and the feeling inside the cave is more profound. The water quality is clear, the river course is deep and winding, or into pools, or into moors, or into waterfalls, changeable and infinite. Especially the lifting device will take tourists and boats up. This is the first experience. I feel a little afraid of falling down. In fact, it is very safe. The children say they want to rise again. It feels more exciting. What I want to say is that there are guides in the way of exploring the cave. Later, there are no people in the most part of the cave, only three of us. We can't see anyone anymore. We can only hear the sound of the water. At that time, I was very nervous. I thought of seeing someone lost in the cave on TV, and I was scared to shout and run again. Interesting! It's worth recommending.