 The Imperial City was surrounded by a wall and accessed through seven gates and it includes historical places such as the Forbidden City, Tiananmen, Zhongnanhai, Beihai Park, Zhongshan Park, Jingshan, Imperial Ancestral Temple, and Xiancantan.In the Yuan dynasty, Beijing was known as Dadu, and the Imperial City formed the centre of the city.In 1368, the Ming armies conquered Dadu, and changed its name to "Beiping" (the two characters meaning "north" and "peace" or "pacified"), with the capital moved to Nanjing.