The Great Pyramid of Khufu at Giza is the oldest of the Seven Wonders of the Ancient World and the only one still standing. It was the tallest structure on Earth for approximately 3,800 years. Its base is aligned to the cardinal directions with an accuracy of 0.05 degrees. Its four sides vary in length by less than 8 centimeters. It contains roughly 2.3 million blocks of stone with an average weight of 2.5 tonnes, and some weighing up to 80 tonnes.
It was built, according to mainstream Egyptological scholarship, in approximately twenty years, around 2560 BCE, during the reign of the pharaoh Khufu of the Fourth Dynasty. And it was built by Egyptian workers — not slaves, not extraterrestrial visitors, but organized, fed, housed, and paid human beings who left enough material evidence for us to understand a great deal about how they did it.
The Workforce
For a long time, the workforce that built the pyramids was assumed to be slave labor based on the biblical Exodus story. This assumption was undermined decisively by archaeology. In 1990, a tourist’s horse tripped in the sand near Giza and uncovered the edge of a cemetery. Subsequent excavation revealed the burial ground of the pyramid workers themselves. These were not mass graves of anonymous slaves. They were individual tombs, some with inscribed stelae naming the deceased and their occupation, equipped with grave goods that indicated they were valued members of society.
Further excavation found the workers’ village: bakeries, breweries, fish-processing facilities, administrative buildings, and sleeping quarters. Analysis of the animal bones found there indicated that the workers ate beef regularly — not the diet of slaves, but of well-fed laborers. Administrative papyri found at Wadi al-Jarf in 2013, written by an official named Merer, provide a day-by-day account of his team’s work transporting limestone blocks from Tura to Giza. These are the oldest papyri ever found, and they describe an organized, professional operation.
The workforce is now estimated at around 20,000 to 30,000 workers at peak, divided into permanent skilled workers who lived at Giza year-round and rotating crews of conscripted laborers who served for a few months as their civic obligation — similar to later Egyptian corvee labor. This was hard, dangerous work, and the skeletal remains show evidence of injuries and arthritis. But it was compensated work performed by free Egyptians, not enslaved people.
The Logistics
The core material of the Great Pyramid is limestone quarried from the Giza plateau itself, directly adjacent to the construction site. The finer white limestone used for the outer casing came from Tura, across the Nile, and Merer’s papyri document its transportation by boat. The granite used for the interior chambers came from Aswan, 800 kilometers to the south.
Moving 2.3 million blocks of stone, most of them weighing 2 to 3 tonnes, required moving an average of roughly 300 blocks per day over the twenty-year construction period. The most widely accepted method for moving stones across the plateau involves wooden sledges pulled over wetted sand or clay — wet sand dramatically reduces friction, and a 2014 study using a scale model confirmed the technique can work with the labor force available. Rollers and levers would have been used for additional mechanical advantage.
Getting the stones up as the pyramid rose is more contested. Ramps of some kind are almost universally accepted — the debate is about their form. A single frontal ramp long enough to reach the pyramid’s peak would have required more material than the pyramid itself and left substantial remains. The currently favored hypotheses involve either a spiral ramp hugging the pyramid’s outer face, or a combination of exterior ramp and interior notched passage that was later filled in. Neither has been definitively proven, partly because the outer casing was stripped away in antiquity for building material, removing much of the evidence.
The Engineering
The precision of the Great Pyramid’s construction was not accidental. The base is nearly a perfect square, level to within 2.1 centimeters across its entire 230-meter extent. This was achieved using standard Egyptian surveying tools — plumb bobs, set squares, and a sight tube — combined with careful astronomical alignment. The near-perfect orientation to true north was probably achieved by sighting the circumpolar stars, which trace a circular path around the celestial north pole, and bisecting the arc they travel.
The interior of the pyramid is almost as remarkable as its exterior. The Grand Gallery — a soaring corbelled passageway 8.5 meters high and nearly 47 meters long — leads to the King’s Chamber, a room constructed entirely of red Aswan granite. Above the chamber, five separate stress-relieving chambers were built to distribute the enormous weight of the stone above without crushing the room below. The builders clearly understood structural engineering at a sophisticated level.
In 2017, a collaboration of physicists using muon tomography — essentially X-raying the pyramid with cosmic ray particles — detected a large previously unknown void above the Grand Gallery. Its purpose is unknown. The pyramid may still have secrets to reveal.
Why?
The obvious question is why. Why did a society devote such resources to building tombs? The answer lies in the theology described in the pharaohs article and the gods article. The pharaoh was a god made human, the maintainer of cosmic order. His successful transition to the afterlife was not merely a personal matter — it was essential to the continued functioning of the universe. The pyramid was simultaneously a tomb, a resurrection machine, and a statement about the nature of royal power.
The pyramid shape itself carried meaning. The Egyptian word for pyramid, mer, may relate to the concept of ascension. The slope of the sides, pointing toward the sky, was a visual ramp connecting earth and heaven. The pyramid’s capstone, the benben, was associated with the primordial mound that arose from the chaos waters at the moment of creation. Building a pyramid was, in the Egyptian framework, an act of cosmological significance.
Whether or not one accepts that framework, the achievement itself is undeniable. Twenty thousand workers, twenty years, and the right side of a mountain of limestone later, a civilization had built something that would still be standing 4,500 years after the last one finished work.