The Great Pyramid of Giza, a monument of wisdom and prophecy, was built as a tomb for Pharaoh Cheops in 2720 B.C. Despite its antiquity, 1 aspects of its 2 make it one of the 3 great wonders of the world. The four sides of the pyramid are aligned almost exactly on the north, south, east, and west – an 4 engineering feat. Ancient Egyptians were great astronomers, so computations for the Great Pyramid were based on 5 observations.