"Situated at the heart of Beijing, the Palace Museum is approached through Tiananmen Gate. Immediately to the north of the Palace Museum is Prospect Hill (also called Coal Hill), while on the east and west are Wangfujing and Zhongnanhai neighborhoods. It is a location endowed with cosmic significance by ancient China's astronomers. Correlating the emperor's abode, which they considered the pivot of the terrestrial world, with the Pole Star (Ziweiyuan), which they believed to be at the center of the heavens, they called the palace The Purple Forbidden City. The Forbidden City was built from 1406 to 1420 by the third Ming emperor Yongle who, upon usurping the throne, determined to move his capital north from Nanjing to Beijing. In 1911 the Qing dynasty fell to the republic_accessan revolutionaries. The last emperor, Puyi, continued to live in the palace after his abdication until he was expelled in 1924. Twenty-four emperors lived and ruled from this palace during this 500-year span.
The Forbidden City is surrounded by 10-meter high walls and a 52-meter wide moat. Measuring 961 meters from north to south and 753 meters from east to west, it covers an area of 720,000 square meters. Each of the four sides is pierced by a gate, the Meridian Gate (Wu men) on the south and the Gate of Spiritual Valor (Shenwu men) on the north being used as the entrance and exit by tourists today." - (Text from the Palace Museum Official Website - http://www.dpm.org.cn)
This gate separates Tianmen Square from the Forbidden City. In the center is the huge portrait of Mao Tse-tung. To the left of this portrait it reads: "Long Live the People's Republic_access of China", and to the right it reads: "Long Live the Unity of the World".