Introduction to Yanyu Tower: It is located on Qinglian Island to the north of Ruyizhou, the summer resort. It was built in the fifteenth year of Qianlong's reign (1780), imitating the Yanyu Tower in Nanhu (Yuanyang Lake) in Jiaxing, Zhejiang. The building runs from south to north, with a gate hall in the front and a two-story building in the back. It has red pillars and green tiles. It is five rooms wide and two rooms deep. It has a single eaves and is surrounded by corridors. In the middle of the upper floor, there is a plaque inscribed "Misty Rain Tower" written by Emperor Qianlong. Yanyu Tower is the highest point of Chenghu Lake. Looking from a distance from the railing, you can clearly see Wanshuyuan, Rehe Spring, Yongyou Temple, etc. In summer and autumn, the lotuses bloom in the lake, and the lake is filled with mist, which looks like smoke and clouds. It is a unique scenery.