There are no more famous ancient sites within Egypt or for that matter elsewhere in the world than the Great Pyramids of Egypt at Giza. They have been both a main destination for tourists and a source of imaginative thoughts to the world for over three thousand years. The Great Pyramids of Egypt at Giza are without question an icon, most associated with the country.
However, there are actually over one hundred pyramids in Egypt, many of which are relatively unknown to anyone, who is not an ancient Egypt enthusiast. All, but a very few, are grouped around and near the City of Cairo, south of the Nile Delta. Otherwise, only one royal pyramid is known in southern Egypt (at Abydos) that was built by Ahmose, a founder of the 18th Dynasty and Egypt's New Kingdom. It may have also been the last royal pyramid built in Egypt.
The Pyramids of Egypt were, for the most part, tombs for the Pharaohs, aimed to shelter and safeguard a pharaoh's soul, contained in his corpse with a help of mummification. You must, nevertheless, question the reason why Egyptian rulers chose this particular shape and for that matter why they built them so large. The tradition of pyramid building started in Ancient Egypt as a sophistication of the idea of a mastaba or "platform", covering the royal tomb. Later, several stacked mastabas were used. Early pyramids, such as the Step Pyramid of King Zoser (Djoser) at Saqqara by the famous Egyptian architect, Imhotep, illustrate this connection.
As far as the great size of many of the Pyramids in Egypt is, we can really only surmise that the Pharaohs were making a statement about their own power and, perhaps, about the glory and strength of their country. Nonetheless, it should also be remembered that many of the latter pyramids were not nearly as large as the Great Pyramids at Giza (and elsewhere).
The Pyramids of Egypt evolved. The first of them were not perfectly formed pyramids. In fact, they were not true pyramids at all with smooth sides and points at the top. Pyramids continued to evolve throughout their history. There were failures as well as glorious successes until finally they got it right with what was probably the first smooth sided true pyramid, built at Meidum.
Soon after the first pyramids were built, their form became somewhat standardized. Royal pyramid complexes contained a main pyramid, a courtyard, surrounding the main pyramid, a much smaller cult pyramid for the king's soul, a mortuary temple, situated next to the main pyramid, an enclosure wall and a causeway that led down to a valley temple. Some pyramid complexes consisted of subsidiary, smaller pyramids for family members and most were surrounded by some sorts of tombs for family members.
Our thinking on pyramids has changed considerably over the years. Many of us, who are a bit older, were taught that the pyramids were built using Jewish slave labor, which is a fabrication of immense proportions. Nevertheless, most pyramids of Egypt were built long before the Jews made their appearance historically. Contrary to some popular depictions, the pyramid builders were not slaves or foreigners. Excavated skeletons show that they were Egyptians, who lived in villages, developed and overseen by the pharaoh's supervisors.