In this provocative collaboration from two Egyptology outsiders, Robert M. Schoch, Ph.D., and Robert Bauval combine their decades of research to show how the Sphinx is thousands of years older than the conventional Egyptological timeline and was built by a long forgotten pre-Pharaonic civilization. They examine the known history of the Sphinx, contrasting what Egyptologists claim with prominent historical accounts and new research, including updates to Schoch's geological water weathering research and reanalysis of seismic studies. Building on Bauval's Orion Correlation Theory, they investigate the archaeoastronomical alignments of the monuments of the Giza Plateau and reveal how the pyramids and Sphinx were built to align with the constellations of Orion and Leo. Analyzing the evidence for a significantly older construction phase at Giza and the restoration and recarving of the Sphinx during the Old Kingdom era, they assert that the Sphinx was first built by an advanced pre-Pharaonic civilization that existed circa 12,000 years ago on the Giza Plateau, contemporaneous with the sophisticated Göbekli Tepe complex.