the great wall of china

"A wondrous engineering feat rarely matched in the history of the world, the 1,500-mile-long Great Wall stretches the whole length of China's northern borders from the shores of the Pacific to the Gobi Desert in central Asia. It is so prominent on earth that astronauts say it is the only manmade structure they can see with the naked eye from space. Originally, the 2,000-year-old Great Wall was constructed to shield the ancient empire from barbarians by shutting itself away from the outside world, but today it is r…