:Triggers Egyptological Nonsense Shield:
There is so much speculation, elaboration and fabrication about the monumental structures of Egypt it is hard to know where to start! Even the 'official' history of the nation is at least partially a fantasy as two pharaohs have been eliminated from the records.
Altho' the amount of labour involved is high, there is nothing mysterious or impossible about the construction of largely solid pyramidal structures. Even the more elaborately engineered temple complexes do not require any unimaginable devices to make them. By far the simplest explanation as to how they were built is:
Rimmer: No, Lister, I mean like the pyramids. How did they move such massive pieces of stone without the aid of modern technology?
Lister: They had massive whips, Rimmer. Massive, massive whips.
Of course the truth is that the pyramids were a national undertaking for the reverence of the leaders that were considered divine. Slave labour was not used in their construction and it was an honour to be part of the labour force (with decent pay and conditions too). The expense involved was enormous by Egypt had the deep coffers required for such projects back then.