China's Great Wall is crumbling
Construction on China's Great Wall began in the 3rd century BC and was expanded significantly by the Ming Dynasty between 1368 and 1644.
In the years since, however, its size has been slowly deteriorating.
According to a report by the Beijing Times, a survey performed by the Great Wall of China Society revealed the sprawling site is now about a third smaller than it once was.
Depending upon whether it's measured in terms of individual pieces or total span, the structure now stretches around 6,000 to 13,000 miles.
Of that, more than 700 miles of the wall are in extremely poor shape.
Primary causes for the decline were identified as the effects of nature and theft.
Over the past several hundred years, wind and rain have taken a toll. Plants growing on the wall have also accelerated its decay.
Some of the towers are so dilapidated it's believed they could be wiped out by a single storm.
Not helping matters is that stealing bricks has become common in some areas.
They're often used to build houses, and some are sold as souvenirs.
Though protection regulations have been put in place, the resources to enforce them are often not available.
See photos of the Great Wall throughout the years: