There are three main Pyramids of Giza: The Great Pyramid of Khufu, the Pyramid of Kafhre and the pyramid of Menkaura.
Each of the larger pyramids were constructed as tombs for one of the kings of Egypt. The smaller pyramids surrounding them were constructed often for their wives.
The pyramids are massive structures. The Pyramid of Khufu, the largest single building in the world, has a base that covers nearly nine acres.
Scholars believe it took a steady group of at least 20,000 laborers to construct the pyramids. They are made from limestone and granite bricks that weigh as much as 2.5 tons, each.
There are certain mysteries that surround the pyramids, including how they were constructed. They are also built in a nearly straight line that may have something to do with alignment to the stars.