There has been some serious evidence that has come to light in recent years that the great Sphinx at Giza is actually much, much older than anyone ever imagined. Orthodox Egyptology would have us believe that the Sphinx was created in the Old Kingdom, ca. 2500 BC by the Pharaoh Chephren/Khafre, whom they would also have us believe created the Second Pyramid at Giza. Egypt was almost as dry and arid then as it is today. It was actually so dry that the ancient Egyptian language actually didn't even have a word for rain. However, independent Egyptologist John Anthony West and geologist Robert Schoch of Boston University have persuasively shown that the erosion patterns visible on the body of the Sphinx could only have been produced by rainwater. There are rolling and undulating patterns all over the body of the Sphinx that are characteristic of erosion by heavy rains and the resulting rainwater runoff. Erm... But the last time it significantly rained in Egypt was about 8000 years ago, so the Sphinx must have conservatively been made sometime between 7000 BC and 5000 BC before arid conditions began to set in that have continued to the present day. This is the latest date that Schoch gives for the creation of the Sphinx. There were, however, heavy if sporadic rains in the days of the Old Kingdom (4000 BC to 2000 BC), but Schoch judged the erosional profile of the Sphinx to have been created by a very long period of regular and heavy rainfall since the carving of the monument, and so did not consider this to be the primary factor for explaining the observed profile. These findings were later endorsed by the American Geological Society, and most geologists do not dispute Schoch's conclusions. West, however, goes even further and asserts that the Sphinx is even older than that, pushing its date to the turbulent period around 10,000 BC, just after the end of the Pleistocene ice age, when heavy and torrential rains covered much of North Africa, because he considers the Sphinx to be an equinoctial marker, a monument created to commemorate the precession of the equinoxes. Carved in the shape of a lion, it would seem to mark the age of Leo, which last happened between 10,970 BC to 8810 BC. He also argues for this far earlier date to counter Hawass and Lehner's arguments below.
Further evidence comes from the Valley Temple about a hundred meters from the Sphinx at the banks of the Nile. This very strange temple has been cut out of huge cyclopean limestone blocks, each weighing an average of 200 tons, limestone blocks that Schoch showed also came from the Sphinx enclosure. These titanic limestone blocks making up the temple are also eroded with a similar erosional pattern, and they were covered with younger granite facing stones that seem to have been carved to fit with the erosional pattern. It seems that the Sphinx enclosure was artificially excavated, and the limestone removed was used to make the Valley Temple. By Khafre's time, this temple was already so old and badly eroded that he or some other Old Kingdom Pharaoh decided to restore it by covering the eroded stones with granite facing blocks.
Of course, the timeframe all of this geological evidence implies is anathema for orthodox Egyptologists such as Dr. Zahi Hawass (the present Egyptian director of the Giza sites) and Dr. Mark Lehner of the University of Chicago, who debated with West and Schoch on this topic at great length, as it disrupts their whole theory of Egyptian history. It implies that there was a high civilization 8,000 to 10,000 years ago, when there were supposed to be no civilizations at all. They responded by making ad hominem attacks on West that he didn't have a Ph.D (as if erosional patterns would lie to people without doctorates), and by asking "where is the rest of the civilization" that created the Sphinx at such an early date could be. This is another reason why West prefers incredibly early date he suggests; the geography of Egypt was very different then, and the many thousands of years would have buried deeply or ruined most of this hypothetical lost civilization's traces. If Schoch's later dates are correct, West believes that some evidence of that civilization would probably have been found by now, along with the ancient predynastic artifacts that have been found. Nevertheless, the argument misses the point and is fallacious: lack of evidence to the contrary does not constitute proof. To this date, no one has come up with a convincing refutation of West and Schoch's conclusions.