The most comprehensive and technologically advanced survey of
China's Great Wall has discovered the ancient monument is much
longer than previously estimated, state media reported Monday.
However the project has also shown the World Heritage-listed
site is in danger of disappearing in many places due to road
construction and other forms of development, as well as extreme
weather, the China Daily said. The wall, built over centuries to
keep foreigners out of China, stretches for 8,851.8 kilometres
(5,488.1 miles), much further than common estimates of 5,000
kilometres, according to the findings of the survey. The
defensive structure includes 6,259.6 kilometres of actual wall,
plus 359.7 kilometres of trenches and 2,232.5 kilometres of
natural barriers such as hills and rivers. The two-year mapping
project, carried out by the State Administration of Cultural
Heritage, involved using global positioning systems and infra-
red technology. Previous estimates were mainly based on
historical records, rather than physi