The English Egyptologist Flinders Petrie would compare the precision of the casing stones to being “equal to opticians’ work of the present day, but on a scale of acres.” He further remarked that “to place such stones in exact contact would be careful work; but to do so with cement in the joints seems almost impossible.” One of the original casing stones from the Great Pyramid, saved from the rubble and now displayed in the British Museum. Photo by CaptMondo, CC BY 2.5. Many theories attempt to answer the question of how this architectural wonder was accomplished, and oftentimes the answers contradict one another. The Greeks believed that slave labor was used, but more contemporary theories assert that the building of the Great Pyramid took the workforce of probably tens of thousands of skilled workers organized in groups hierarchically. https://www.thevintagenews.com/2016...-was-removed-to-build-mosques-and-fortresses/