Introduction to Fuhai: Fuhai, also called East Lake, has a water surface area of about 520 acres, and is 500 to 600 meters wide from east to west and north to south. It is the center of the park and the largest lake in the park, so it is called " ocean". Fuhai is a large artificial lake formed by digging lakes and stacking mountains when the garden was first built. It can not only regulate the temperature in the garden, making it refreshing and pleasant in summer; it also makes the Old Summer Palace look empty when there is thick fog or rainy days. In order to pursue the illusion of immortals living in seclusion, Emperor Yongzheng scattered fairy mountains and pavilions around Fuhai, and named East Lake Fuhai according to the meaning of "Xu Fuhai seeks in the sea".