If you thought the Great Wall of China was long, think again. A newly discovered 80-kilometre section in the northwest has just made it even longer. Hidden by shifting sands on the southern slope of Helan Mountain in Ningxia - about 40km west of Yinchuan - this freshly uncovered piece of the wall built in 1531 remained hidden for hundreds of years until it was dug up early last week. While a major discovery, the unearthing of new sections of the wall is not unique. Earlier this year archeologists found a 2,000-year-old section which included two fortified castles dating back to 206 BC. Stretching about 6,000km over five provinces from the Shanhaiguan Pass in the east, to the Jiayuguan Pass in the Gobi Desert, this magnificent structure weaves its way across grasslands, deserts and treacherous terrain like a writhing dragon. Contrary to popular belief, the Great Wall is not one long, continuous structure, but rather a series of walls built and rebuilt by different dynasties over many centuries. Construction began 2,000 years ago in the Qin dynasty (221-207 BC). The main function of the wall was to defend the country against marauding nomads. But it also acted as a kind of ancient highway, transporting men and goods across difficult terrain, and serving as a link to the Silk Road. Traversing as far as the eye can see, the brick and granite structure is also known as the Wan Li Zhang Cheng (million-mile-long fort). It's overwhelming to think how each stone was laid on the craggy mountain tops just north of Beijing, where merely walking this restored section of the wall called Badaling is enough to make you work up a sweat. Today, parts of the Great Wall have been pulled down to make way for railway lines, roads and modern industry. Others have crumbled away with time - eroded by the elements and lying in ruins. Efforts to restore certain sections have paid off, and in 1987 the wall was declared a United Nations World Heritage site. There are many myths and urban legends surrounding the structure. Estimates put the rate of construction at about 16km a day, meaning it would have taken a staggering 10 years to finish the first section of the wall. Many legends tell of how countless lives were lost during construction, and of how the bodies were buried within the wall. The actual length of the wall has never been confirmed, but the Guinness Book of Records rates it the longest wall in the world - almost three times the length of the United Kingdom. Which facts are true and which are not hardly seems relevant to today's China. Instead, since the 20th century the wall has become a national symbol of growth and evolution. And while the pace of modern life gathers momentum in Beijing, the timeless wonder of the wall will continue to make it one of the most sought-after attractions in the world. Particularly if it just keeps on getting longer.