Lying at the center of Beijing, the Forbidden City, called Gu Gong, in Chinese, was the imperial palace during the Ming and Qing dynasties. Now known as the Palace Museum, it is to the north of Tiananmen Square. Rectangular in shape, it is the world's largest palace complex and covers 74 hectares. Surrounded by a six meter deep moat and a ten meter high wall are 9,999 buildings. The Forbidden City is divided into two parts. The southern section, or the Outer Court was where the emperor exercised his supreme power over the nation. The northern section, or the Inner Court was where he lived with his royal family. Until 1924 when the last emperor of China was driven from the Inner Court, fourteen emperors of the Ming dynasty and ten emperors of the Qing dynasty had reigned here. Construction of the palace complex began in 1407, the 5th year of the Yongle reign of the third emperor of the Ming dynasty. It was completed fourteen years later in 1420. It was said that a million workers including one hundred thousand artisans were driven into the long-term hard labor. Stone needed was quarried from Fangshan, a suburb of Beijing. It was said a well was dug every fifty meters along the road in order to pour water onto the road in winter to slide huge stones on ice into the city. Since yellow is the symbol of the royal family, it is the dominant color in the Forbidden City. However, there is one exception. Wenyuange, the royal library, has a black roof. The reason is that it was believed black represented water then and could extinguish fire. Leave through the north exit of the Forbidden City, cross the road and enter Jingshan Park (also known as Coal Hill). Climbing the hill gives great panoramic views over the rooves of the Forbidden City and surroundings.