great wall of china

great wall of china

Malcolm Moore in Shanghai 11:34AM BST 20 Apr 2009

Previous estimates, based mainly on historical records, put the monument at 3,106 miles long. But a survey using GPS and infra-red technology found it stretched for 5,488 miles. Researchers discovered unknown parts of the wall by trekking through the mountains and deserts of northern China.

Chinese state media said 70 per cent of the monument was a wall, while the rest was a combination of trenches and natural barriers such as hills and rivers. The wall roughly traces a line that separated China from Inner Mongolia.

The first sections are more than 2,000 years old but were rebuilt and extended during the Ming Dynasty, from the 14th to 17th centuries.

Shan Jixiang, the director of the State Administration of Cultural Heritage, said the wall, a World Heritage site, was in danger of falling into ruin in several places. Less than 10 per cent was in good condition, the department said, with only a further 20 per cent in “average” condition.

“The Great Wall is under great threat — climate change and the country’s massive infrastructure building being the biggest two,” Mr Shan told the China Daily newspaper.

He said the wall “would not lose even one metre more” to lack of maintenance.