The BBC reports that a major mapping project has found the Great Wall of China to be much longer than previously thought.
A two-year government mapping study found that the wall spans 8,850km (5,500 miles) - until now, the length was commonly put at about 5,000km.
Previous estimates of its length were mainly based on historical records.
Infra-red and GPS technologies helped locate some areas concealed over time by sandstorms, state media said.
The project found that there were wall sections of 6,259km, 359km of trenches, and 2,232km of natural defensive barriers such as hills and rivers.
Experts said the newly-discovered sections of the wall were built during the Ming Dynasty (1368-1644), and stretch from Hu Mountain in northern Liaoning province to Jiayu Pass in western Gansu province.
The project will continue for another 18 months in order to map sections of the wall built during the Qin (221-206BC) and Han (206BC-9AD) Dynasties, the report said.
More news, and a map of the new discoveries, are at the link.
The Great Wall has always fascinated me. It's one of the earliest examples of putting one's faith in fixed positions instead of mobility. It's also one of the earliest failures of such a policy - because the tribes it was intended to keep out, ended up overrunning China, again and again. It's long since been proven that to tie down your defenses - and defenders - in a fixed location is merely to allow a more mobile enemy to move around you, or mass his forces to overwhelm and break through one specific point in your defenses, while your defenders are spread thin trying to cover them all. That done, he can come in behind you and cut your lines of supply. The result is inevitable.
One wonders how many millions of Chinese died building and defending the Great Wall before that truth was realized?