The most famous Egyptian pyramids to be built are Great Pyramids of Giza, located in outskirts of present-day Cairo. There are over 100 Egyptian pyramids of various sizes, and over 50 more in neighboring Sudan. However, three Great Pyramids of Giza earn their fame by being largest of these.In most popular pictures of Pyramids of Giza, like one shown below, middle pyramid, that of Khafre (Chephren), appears larger due to angle and because it was built on higher ground. The largest pyramid is actually Great Pyramid of Khufu (Cheops), one on left.
The Great Pyramid of Khufu
Contrary to popular belief, not all Great Pyramids of Giza are considered part of Seven Wonders of World. Only largest, Great Pyramid of Khufu, is a member, and is only one of Seven Wonders that still stands. Egypt was also home to another of Seven Wonders of World, Lighthouse of Alexandria, which was destroyed long ago.
The Pyramid of Khufu has a height of 145 m (475 ft) and a base area of 52,400 sqm (562,500 sqft). That area is large enough to fit over 20 Olympic-size swimming pools! And for thousands of years, until rise of modern-day skyscrapers, pyramid was tallest building in world.
What makes pyramid an architectural triumph and one of Seven Wonders of World is fact that rocks used in its construction each way more than 2 tons. And there are more than 2 million of those rocks.
Greek travelers to ancient Giza wrote that it took a hundred thousand slaves 20 years to construct pyramid. However, since they visited Egypt more than 2 thousand years after Egyptian pyramids were built, truth of their accounts are suspect. Modern engineers estimate that it would likely take less people and less time to build pyramid using technology that was available at that time.