Throw away your pictures of slaves pulling giant blocks of stones on rollers. The pyramids are not built of natural stone but poured stone. The Egyptian engineers knew how to make super-concrete. It was much easier to raise barrels of liquid concrete and cast the stones in place.
For more details, see "Super Concrete in the U.S. Military, Iran … and the Pyramids?", David Hambling, Wired, 2009-10-22.
