Numerous archaeologists are raising the question of where the missing counterpart to the Great Sphinx at Giza is located: the solitary nature of the ancient half man, half lion sculpture is an anomaly in ancient Egypt, as virtually every other depiction of a sphinx comes in pairs. These pairs are depicted as male and female, embodying the various representations of duality. If this theory is true, then where is the Great Sphinx’s equally Great Sister — and what happened to erase such a massive monument from history?

Egyptologist Bassam El Shammaa has been studying clues regarding the lost sphinx for over a decade, and believes that the Sphinx’s sister stood guard with her brother, side-by-side on the Giza plateau. "Every time we have to deal with the solar cult, we should discuss of one lion and one lioness facing each other, posing parallel to each other or sitting in a back-to-back position," explains El Shammaa.

Documentary evidence, such as the Dream Stela, believed to have been inscribed by Thutmosis IV and located between the Great Sphinx’s paws, depicts two sphinxes. But El Shammaa says that the key lies in the Pyramid texts, that include the phrase "I was with two, now I am with one." He believes that this indicates that something catastrophic happened to the missing sphinx, in particular a powerful lightning strike that obliterated the sculpture.

As for where the remains of the missing monument are, El Shammaa believes he has found the spot, on the opposite side of the long causeway to the right of the Great Sphinx, running from the mortuary temple that stands in front of the Pyramid of Khafre. Using images from a satellite survey of the Giza Plateau, Ell Shammaa points to an area of increased density there that corresponds to the size and position of the extant Sphinx.

Other researchers agree with El Shammaa’s theory, although archaeologist Michael Poe believes the site of the Sister Sphinx lies on a point on the opposite bank of the Nile River, facing her brother on the western bank.

"Have you ever seen just one Sphinx in later Egypt that didn’t have another? Not only did the ancient Egyptians mention the second Sphinx, but so did the Greeks, Romans, and Muslims. It was destroyed between 1,000 and 1,200 AD," posits archaeologist Michael Poe.

"At the access to buildings and temples there are two Sphinxes, side by side, but on the avenue or approach to the temple, they are facing each other," posits Poe. "The Nile is Egypt’s Avenue, and it divides the North and South. Countless ancient writings about the two Sphinxes suggest that they were facing one another." Poe goes on to say that the female Sphinx was destroyed in an unusually high flooding of the Nile, with the remains removed by local villagers for material to rebuild their homes.

Other researchers that agree with the Twin Sphinx theory are authors Gerry Cannon and Malcolm Hutton, whom believe that the missing sculpture lies under a mound on the other side of the roadway to the Great Sphinx’s left; and Graham Hancock and Robert Bauval, having outlined their own research in their 1997 book, The Message of the Sphinx.