Egyptian Pyramids are among the world's top tourist attractions, and the subject of both serious study and wild speculation. Credit: sxc.hu View full size image

Egypt's Great Pyramids at Giza are one of the world's most amazing achievements. Built during the reign of Cheops, around 2530 B.C., the largest pyramid towers nearly 500 feet (150 meters) high and covers 13 acres (5.2 hectares). They are among the world's top tourist attractions, and the subject of both serious study and wild speculation.
Many people, misled by mystery-mongering books , Web sites, and TV shows, believe that the pyramids are a classic unexplained mystery.

Among archaeologists, historians, and Egyptologists, however, there's no real mystery. The methods by which the pyramids were constructed are pretty well understood and documented, and have appeared in many places including Mark Lehner's book, The Complete Pyramids: Solving the Ancient Mysteries (Thames & Hudson, 1997).
Rocks were quarried from as far as 600 miles (960 kilometers) away in Aswan and transported to Giza, probably on rafts down the Nile during the rainy season. A level surface was prepared (again, using Nile floodwater for accuracy), and a causeway was built from the Nile toward Giza. The stones were pulled on sleds or over rolling logs near the pyramid, where stonemasons prepared the slabs. Once the four sides of the foundation of the pyramids were set, each successive layer was addedsmaller in area but higher off the ground.
There are several ways that the heavy blocks could have been added to the top. Side ramps made of either earth or wood could have been built along the sides of the pyramids, or the workers might have simply built an earthen ramp against one side and dragged the blocks up on logs. It was an incredible amount of work, and required tens of thousands of workers over decades.
Of course there are no photographs of the pyramid being built, and the engineers didn't leave detailed blueprints. Much of the evidence comes from archaeology, and there is about as much evidence for how the pyramids were built as there is for any other large-scale construction dating back 5,000 years.
The tombs of workers who constructed the pyramids were recently found, and Egypt's chief archaeologist Zahi Hawass noted that they demonstrated that the pyramids were built by paid laborers instead of slaves. This debunks many of the wild theories by writers such as Erich von Daniken, who has written that the pyramids were not made by humans but instead by aliens. 

The idea that ancient peoples were not intelligent enough to build the pyramids is an insult, as the pyramid shape is one of the most obvious, basic and stable forms of construction there is. If you wanted to build something large in ancient times that would last for millennia, a pyramid would actually be the easiest and best design.
The only real mystery surrounding the pyramids is why people still believe their origin is a mystery
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