The Great Wall of China

There is a popular belief that The Great Wall of China has the distinction of being the only man-made work of architecture that is visible from outer space. It cannot be seen from outer space—at least as far as American astronauts are concerned, for that is what they have reported. The Great Wall of China is, however, the longest and most ambitious, large scale construction project in the history of mankind—a magnificent wall that stretches for 5,500 miles across China. That figure includes some natural areas that function as a defense against intruders. The wall was built to keep Mongols and other barbarians out and to help preserve Chinese culture. So it served two purposes: military defense and cultural reinforcement.