Beihai Park is a public park and former imperial garden located in the northwestern part of the Imperial City, Beijing. First built in the 11th century, it is among the largest of all Chinese gardens and contains numerous historically important structures, palaces, and temples. Since 1925, the place has been open to the public as a park. It is also connected at its northern end to the Shichahai. The park has an area of more than 69 hectares (171 acres), with a lake that covers more than half of the entire park. At the center of the park is an island called Jade Flower Island (琼华岛; 瓊華島; Qiónghuádǎo), whose highest point is 32 meters (105 ft). Beihai literally means "Northern Sea". There are also corresponding Central (Zhonghai) and Southern (Nanhai) "Seas". These latter two are joined inside a complex of buildings known after them as Zhongnanhai; it is the home of China's paramount leaders.