Contrary to popular belief, the Great Wall of China is not the only man made object on earth that is visible from space; in fact, the Great Wall is barely discernable, and only under perfect conditions. Low earth orbit(160-350 miles up) is the altitude that the space shuttle orbits at. At this "low" level of orbit, many man made objects are viewable to the naked eye, including airports, bridges, dams, and highways. The Wall is only 30 feet wide, and is of a similar color to its surroundings. The myth that "the Great Wall is the only man-made object visible from the moon" started in 1938 when the book "Second Book of Marvels, the Orient" was published, stating that "Astronomers say that the Great Wall is the only man-made thing on our planet visible to the human eye from the moon." Something that is almost invisible at 180 miles certainly isn't visible at 237,000 miles.