There are a wide variety of theories associated with the pyramids of Egypt. The most outlandish theories suggest that they were built by space aliens. However, studies have conclusively shown that the great pyramids we find today are human achievements. The first pyramids were built in ancient Egypt, the first of which was the tomb of King Zhoser (c. 2668-2649 BCE). Over the next thousand years, each major Egyptian pharaoh received a pyramid for his burial. However, the pyramids were not only graves, but they also served a ritual purpose. The most famous Egyptian pyramids are the three pyramids of Giza, the largest of which is the Pyramid of Cheops, which was completed around 2600 BCE.

The excavation of the building stones of the pyramids began by drawing the dimensions of the stones on a cliff or rock, after which a boulder was cut off. The stones were moved with the help of wooden sleds, as the wheel had not been invented yet. At the construction site, the stone embankments were transported by ferries along the river. The right angles of the edges of the boulders were checked with an angle gauge.

The blueprints of the pyramids were made on clay. The bottom of the pyramids was leveled with hoes, and the wide perimeter was calculated into a square. This formed the base of the pyramid. This had to be done accurately, as even a small dimensional error would have caused large changes in the upper layers. The builders had only ropes, lever arms, and rocks and mud as their aids. Water tanks embedded in small clay tiles acted as level gauges. Giant rock cliffs were towed to the building platforms by men along mud-soaked ramps. 

The limestone boulders used to build the Cheops Pyramid weigh an average of [[$ 2,5-5 $]] tons. In total, the Cheops Pyramid contains over [[$ 2,3 $]] million such boulders. The largest stones on the roof of the tomb weigh about [[$ 40 $]] tons. Back in the day, the Pyramid of Cheops covered more than four acres of land and were [[$ 147 $]] meters high. Today, about [[$ 10 $]] meters are missing from the pyramid's top.

Estimates of the number of builders that helped to construct the Pyramid of Cheops varies a lot. The ancient Greek historian Herodotus estimated that [[$ 100,000 $]] men worked on the Pyramid of Cheops over the course of [[$ 30 $]] years. For their pay they, received bread, radish, and leeks. However, the British egyptologist Wier has suggested that the number of builders was only about [[$ 10,000 $]]. He has justified this as follows: The volume of the Pyramid of Cheops was about [[$ 2,6 $]] million cubic meters. A total of [[$ 2,5\cdot10^{12} $]] joules of work is required to raise this amount of stones. One man can work for about [[$ 240,000 $]] joules a day. According to Wier, lifting the stones required the daily work of [[$ 1250 $]] men over the course of [[$ 23 $]] years. Even more men were needed for the quarrying, shaping and drawing of the stones.