National Geographic - The Great Wall of China

The Great Wall of China is the only man-made structure visible from the moon with the naked eye. Yet it failed to keep the Mongols and Manchus out of China. As you solve this puzzle, you will face a similar challenge to the one that the Ming dynasty faced-how to construct a portion of the Great Wall's northern exterior impenetrable to attack. The object is to construct a section of the Great Wall as shown on the inside panel by using all of the pieces.