It is the largest freestanding sculpture ever carved from a single block of stone, an icon recognised around the globe. The Sphinx, a lion with the face of a mighty pharaoh, towers over the Giza Plateau. Yet it remains one of history's most enigmatic mysteries. Who built it, when and why? Using the latest research, the most advanced technology and the newest discoveries to reveal the Sphinx as never seen before, this program unravels the riddle behind the icon. Could it be time to rewrite the history books? Not a single hieroglyph or "signature" from the people that built it has ever been found on the Sphinx. All circumstantial evidence leads directly to the pyramid-building Egyptians. But this is where the debate begins. Conventional wisdom holds that the Pharaoh Khafre built the Sphinx nearly 5000 years ago, as it is his pyramid that stands behind it and a large stone tablet found between its paws bears his name; however, this tablet was written over a thousand years after the Sphinx's carving, so could it be wrong? A leading archaeologist Rainer Stadelmann explains that Khafre is always represented with a beard, but the Sphinx has none. Even the layout of Khafre's temple and causeway prove problematic. Could the Sphinx actually represent Khafre's father Khufu - the builder of the Great Pyramid of Giza? Architect Jonathan Foyle sketches the Sphinx and compares it with his drawing of Khafre and Khufu taken from known statues. For him it is unmistakably Khufu - could the untouchable theory of Khafre be flawed?