 Hello, I'm Jerry Stewart. Of all the man-made spectacles in history, of all the seemingly impossible feats, there is one that truly sticks out in my mind. This unbelievable man-made structure was built for protection, and the people who spent literally hundreds of years building it thought that once it was completed, it would be uncrackable. But it didn't quite turn out the way they planned. What I'm talking about is what we know today as the Great Wall of China.