Outside of Cuzco, Peru, you’ll find a remarkable walled fortress constructed out of perfectly fitted boulders, some weighing over 200 tons. Known as Saksaywayman, the exact construction date is unknown, although the structure is ancient enough to predate the Incas themselves.
While the function of Saksaywayman as a fortress and a ceremonial location is well documented, the process of how this massive fortification was constructed is still not understood. The gaps between the rocks are so thin that a piece of paper will not even fit between them – engineering that required a massive amount of manpower and technological expertise to assemble.
No one has determined how this process was accomplished although theories abound. Some people believe that a liquid extracted from plants rendered the boulders lighter and more malleable, or that heat allowed the rocks to be forced together. Others think that the building was constructed from a complicated wooden template.
