The Beihai Park in Beijing

The Beihai Park is an imperial garden northwest of the Forbidden City in Beijing. Initially built in the 10th century, it is typical of Chinese gardens. Prior to the end of the Qing Dynasty in 1911 this area was part of the Forbidden City, but since 1925 it has been open to the public.

The Park has an area of more than 700,000 m², with a lake that covers more than half of the entire Park. At the center of the Park is an island called Qióng-huá Island with a highest point of 32 m. In the north of the park there is a large pool called the Taiye Pool connecting the two other pools, which are called the Middle Sea and the South Sea respectively. Therefore the Taiye Pool is also called the Beihai.

Beihai literally means "Northern Sea". There are also corresponding "Central" and "Southern Seas" (Zhongnanhai). The complex of buildings around Zhongnanhai houses China's paramount leaders.

from wikipedia.org