The History of the Great Wall of China

 

The Great Wall of China is a monumental landmark in China and the longest structure ever built by humans. Construction on it started more than two thousand years ago and continued, off and on, for almost a thousand years until 1644. Did you know the Great Wall cannot actually be seen from the moon? However, if you were in a low enough orbit and new exactly where and how to look, you might be able to see it.