Although the limestone scarp at the edge of the Western Desert provided an inexhaustible source of building material, finer stone for casing the pyramids was quarried at Tura across the river, or came from Aswan in Upper Egypt. Blocks were quarried using wooden wedges (which swelled when soaked, enlarging fissures) and copper chisels, then transported on rafts to the pyramid site, where the final shaping and polishing occurred. Shipments coincided with the inundation of the Nile (July–Nov), when its waters lapped the feet of the plateau and Egypt’s workforce was released from agricultural tasks.
Herodotus relates that a hundred thousand slaves took a decade to build the causeway and earthen ramps, and a further twenty years to raise the Great Pyramid of Cheops. Archeologists now believe that, far from being slaves, most of the workforce were peasants paid in food for their three-month stint (papyri enumerate the quantities of lentils, onions and leeks), while a few thousand skilled craftsmen were employed full time. One theory holds that a single ramp wound around the pyramid core, and was raised as it grew; when the capstone was in place, the casing was added from the top down and the ramp was reduced. Other ramps (recently found) led from the base of the pyramid to the quarry.
Whether or not the Ancient Egyptians deemed this work a religious obligation, the massive levies certainly demanded an effective bureaucracy. Pyramid-building therefore helped consolidate the state. Its decline paralleled the Old Kingdom’s, its cessation and resumption two anarchic eras (the First and Second Intermediate Periods) and the short-lived Middle Kingdom (XII Dynasty). By the time of the New Kingdom, other monumental symbols seemed appropriate. Remembering the plundered pyramids, the rulers of the New Kingdom opted for hidden tombs in the Valley of the Kings.