The Forbidden City, the core of the central line, was where the emperors lived. Located in the center of Beijing, it used to be the imperial palace of the Ming and Qing dynasties. Its construction started in 1406, and was completed in 1420. The rectangular palace covers an area of some 720,000 sq. km -- 961 m in length and 760 m in width. It has a total of 9999.5 room spaces (an area enclosed by four poles).

The last Qing emperor Puyi was ousted from the palace complex in 1924. A year later, the Forbidden City was renamed the Palace Museum.

The Forbidden City is China's largest and most intact ancient building complex. It is laid out symmetrically along a north-south axial line. The well-designed palace appears magnificent, solemn and harmonious, representing the long cultural tradition of China and its outstanding architectural accomplishments five centuries ago. It is a truly superb masterpiece in every sense.

The Forbidden City is encompassed by a wall 10 m high, and surrounded by a moat 5.2 m wide. The palace has four entrance gates: the main Meridian Gate (Wumen) to the south, the Eastern Flower Gate (Donghuamen), the Western Flower Gate (Xihuamen), and the Gate of Divine Prowess (Shenwumen) to the South. One has to pass through seven gates to arrive at the Palace of Heavenly Purity (Qianqinggong), the emperors' living quarters. These seven gates, starting from the very southern gate of the imperial city, are: Zhengyangmen, Damingmen, Tiananmen, Duanmen, Wumen, Taihemen and Qianqingmen, which symbolize the celestial Plough.