This 4-minute video explains the internal-ramp theory.
A French architect may have solved the mystery as to how ancient Egyptians were able to move two million stone blocks ~ each weighing about 2.5 tons ~ to construct the Great Pyramid.
A little-known cavity spiraling upward inside the pyramid’s structure seems to support the theory that the 4,500-year-old monument to Pharaoh Khufu was constructed inside out.
The presence of a spiraling inclined interior tunnel contradicts the prevailing wisdom that the monuments were built using an external ramp. "The paradigm was wrong," French architect Jean-Pierre Houdin said recently. "The idea that the pyramids were built from the outside was just wrong. How can you resolve a problem when the first element you introduce in your thinking is wrong?"
He says for centuries Egyptologists have ignored evidence of an internal ramp.To deliver blocks to the 481-foot peak at a reasonable grade, the ramp would extend a mile, and workers would have had to continually increase its height and length as the pyramid rose.