A pyramid is an example of monumental funerary architecture with a square base and sloping, triangular sides. These massive, mountain-like buildings are the burial places of Egyptian pharaohs and serve an important religious and political function: to protect the pharaoh’s soul, or ka, and to aid in the transition of the ka to the afterlife. One of the most famous of all pyramid sites is the Great Pyramids of Giza. The Great Pyramids of Giza, the tallest of which is 450 feet high, were built during the Old Kingdom, c. 2575–2150 B.C.E., and were intended for the rulers of the Fourth Dynasty: Menkaure, Khafre, and Khufu. They were built of granite and limestone and memorialize these rulers as divine beings.