Tian'an men( the Gate of Heavenly Peace), is located in the center of Beijing. It was first built in 1417 and named Chengtianmen( the Gate of Heavenly Succession). At the end of the Ming Dynasty, it was seriously damaged by war. When it was rebuilt under the Qing in 1651, it was renamed Tian'anmen, and served as the main entrance to the Imperial City, the administrative and residential quarters for court officials and retainers. The southern sections of the Imperial City wall still stand on both sides of the Gate. The tower at the top of the gate is nine-room wide and five -room deep. According to the Book of Changes, the two numbers nine and five, when combined, symbolize the supreme status of a sovereign.During the Ming and Qing dynasties, Tian'anmen was the place where state ceremonies took place.
    On October 1, 1949, chairman Mao Zedong proclaimed on Tian'anmen Rostrum the founding of the People's Republic of China. Since then Tian'anmen has been the symbol of New Chine. Chairman Mao's portrait is hung above the central entrance, flanked by two slogans:" Long Live the Great Unity of the Peoples of the World". Today , the splendour of Tian'anmen attracts million of visitors from all over the world. The Rostrum on its top was opened in 1988 to the public for the first time in its history. It offers a panoramic view of the Square and the city proper.