China Central Television Headquarters.

Chinese police train at a military base in Wuhan in central China's Hubei province August 30, 2005. China was setting up elite police squads in 36 cities to counter the threat of "terrorist crimes" and to put down riots, Xinhua news agency reported. Beijing has already stepped up security ahead of the 2008 Olympics. CHINA OUT REUTERS/China Newsphoto.

The Great Wall of China is a series of stone and earthen fortifications in China, built, rebuilt, and maintained between the 5th century BC and the 16th century to protect the northern borders of the Chinese Empire during the rule of successive dynasties.

First built in the mid-6th century during the Northern Qi, Mutianyu Great Wall is older than the Badaling section of the Great Wall. As one of the best-preserved parts of the Great Wall, Mutianyu section of Great Wall used to serve as the northern barrier defending the capital and the imperial tombs.