This is the Palace Museum, also known as the Purple Forbidden City. It is the largest and most well preserved imperial residence in China today. Under Ming Emperor Yongle, construction began in 1406. It took 14 years to build the Forbidden City. The first ruler who actually lived here was Ming Emperor Zhudi. For five centuries thereafter, it continued to be the residence of 23 successive emperors until 1911 when Qing Emperor Puyi was forced to abdicate the throne. In 1987, the United Nations Educational, Scientific and Cultural Organization recognized the Forbidden City as a world cultural legacy.
It is believed that the Palace Museum, or Zi Jin Cheng (Purple Forbidden City), got its name from astronomy and folklore. The ancient astronomers divided the constellations into groups and centered them around the Ziwei Yuan (North Star). The constellation containing the North Star was called the Constellation of Heavenly God and the star itself was called the purple palace. Because the emperor was supposedly the son of the heavenly gods, his central and dominant position would be further highlighted by the use of the word purple in the name of his residence.
Help: imperial adj. 帝王的，至尊的。
abdicate vt. 放弃，退出，退位。
constellation n. 星座。