On weekends, I took part in a one-day tour in Yixing. In the afternoon, I came to Zhanggongdong scenic spot. It was 40 degrees high outside. Once I got to the entrance of the cave, I felt a sense of coolness. The temperature inside the cave was lower. Especially in the small cave, the tour guide had been lobbying for more than 20 degrees all the year round. It was warm in winter and cool in summer. Nature was amazing. Zhanggongdong Scenic Area also includes underground rivers, drifting and playing with mud, which is very interesting. It's a good place for summer vacation.