One suggestion for the formation of the Great Sphinx (Giza, Egypt) is that it began as a yardang. That explanation doesn't make any sense, except possibly for the head. I bring that up because there are those who still seem to think that the "Face on Mars" was anything but a 32 pixel artifact of the Viking orbiter camera resolution. The "Face" has been reimaged (more than five years ago) at much higher resolution, and it is indeed a natural formation, with no symmetry or much else that is remarkable. Also, other natural formations on Mars were attributed by Richard Hoaxland to artificial structures.