Most of the wall now known as the Great Wall of China was built in the Ming Dynasty, between 1368 and 1644. When the Ming fell, the wall gradually fell into disrepair too.
The Great Wall of China has survived assaults by Mongols, Manchus and Mao himself. Now, it faces yet another threat: modernization. The wall has become one of China's main tourist attractions, for both foreigners and the new Chinese middle class.
But its development — some argue, over-development — is triggering concern. Briton William Lindesay hopes his efforts will help preserve and protect China's most famous landmark.