now we come to the central and south seas or zhongnanhai in chinese. it is located on the west of the forbidden city. the area used to be called "three seas," western lake or pool of great secretion it covers an area of 100 hectares (247 acres), of which the seas occupies 47 hectares (116 acres). it was first built in liao (907-1125) and rebuilt in jin (1115-1234), yuan (1279-1368), ming (1368-1644), and qing (1644-1911) dynasties. the area between new china gate on chang'an boulevard in the south and yingtai (sea terrace island) in the north is called the south lake. the area north of the hall of diligent government and south of the temple of endless blessings is called the central lake, which is connected to the south lake by a lock located near the old eastern gate of the area; and the area north of the hall of received brilliance and south of the five-dragon pavilions is known as the north lake or beihai. a long white marble bridge- the golden tortoise jade rainbow bridge (formerly golden sea bridge or imperial river bridge) divides the central lake from the north lake. the water supply for the lakes comes from the jade spring mountain to the west of beijing and enters the city at the gate of moral victory in the north-west corner of the old city limits. the beautiful natural hills and ponds in this area inspired the emperors of the liao dynasty (907-1125) to choose this area as their pleasure park and called the north lake the jade islet. during the jin dynasty (1115-1234), the north lake became the site of the emperors' winter palace. in the yuan dynasty (1279-1368), the lakes were enclosed to become part of the imperial palace in the mongol capital of dadu (great capital), and the lakes were granted a new name--the pool of great secretion. at that time, the lakes were widened and deepened, and the mud dredged from them was heaped up to the north of the forbidden city to form coal hill (prospect) park. the lakes attained their present dimensions of two kilometres from south to north and, at their widest point, 200 metres from east to west. when emperor yongle (1403-1424) of the ming dynasty (1368-1644) rebuilt the imperial palace in 1417, he extended the palace walls to enclose both the former yuan palace and the gardens to the west. hence the ming and qing dynasties, the area became known as the western gardens and continued to serve palace residents as a place of leisure. during the qing dynasty (1644-1911), refurbishment of the area continued on a grand scale, and the majority of the structures and relics, which remain today date from that period. after the overthrown of the qing dynasty in 1911, the central and south lakes were turned into a park for a short period of time and served as the headquarters of the government of yuan shikai (1859-1916). since the founding of the people's republic of china, it has been the headquarters of the central committee of the chinese communist party and the state council of the people’s republic of china. it is now not only the supreme leading centre for the whole nation, but also one of the important places for both the chinese people and international friendly intercourse. the late chairman mao zedong (1893-1976) and the late premier zhou enlai (1898-1976) used to live in it.