The great pyramid of Giza (also known as the pyramid of Khufu or the pyramid of Cheops) is the oldest and largest of the three Giza pyramid complex bordering present day in greater Cairo, Egypt. It is the oldest of the seven wonders of the ancient world, and the only one to remain largely intact.
Egyptologists believe the pyramid was built as a tomb for the fourth dynasty Egyptian pharaoh Khufu (often Hellenized as "Cheops") and was constructed over 20 year period. Khufu's Vizier, Hemiunu, is believed by some to be the architect of the great pyramid.
It is thought that, at construction, the great pyramid was originally 146.6 meters tall, but with the removal of its original casing, its present height is 137 meters. The length of the sides at the base are difficult to reconstruct, pilled the absence of the casing, but recent analyses put them in a range between 230.26 meters and 230.44 meters.
The pyramid remained the tallest manmade structure in the world for over 3,800 years. The accuracy of the pyramid's workmanship is such that the four sides of the base have an average error of only 58 millimeters in length. The great pyramid consists of an estimated 2.3 million blocks which most believe to have been transported from nearby quarries.