Great Pyramids at Giza: View of Sphinx with Pyramid of Khufu to its right

Khufu is the largest of the three pyramids, originally 479 feet tall when the exterior sheathing and cap (pyramidion) was still in place. It is currently 455 feet tall.\u000a\u000aEgyptian governorate just west of Cairo, site of a major royal necropolis of the Old Kingdom capital of Memphis. The necropolis, containing the 4th Dynasty (ac. 2575-ac. 2465 BCE) pyramid complexes of Cheops, Chephren and Mycerinus (Khufu, Khafre and Menkaure) and their associated satellite burials, is divided by a broad wadi into two areas: the higher plateau, with the pyramid complexes, Great Sphinx and mastaba fields, and other private tombs on an escarpment to the south-west. Although Giza's period of greatest importance was during the Old Kingdom (ca. 2575-ca. 2150 BCE), the site underwent revivals in the New Kingdom (ca. 1540-ca. 1075 BCE) and the Saite period (ca. 664-525 BCE). Most of the tombs were robbed in antiquity, and much of the original casing of the monuments has been quarried away, considerably altering their appearance. In the late 20th century the site has come under threat from rising ground water, which is slowly destroying the monuments.