Several theories attempt to explain how pyramids were constructed, but for now, the mystery has yet to be solved. One theory suggests that causeways were used to haul the stone blocks on wooden sleds up the side of the pyramids. The ramps were lubricated with water to reduce friction when hauling the blocks. And that the Egyptians used different tools to build the pyramids including copper pickaxes and chisels, granite hammers, dolerite, and other hard stone tools.