S1, E5: The whole world has its eyes riveted on the Pyramid of Khufu, in Egypt. Yet, nearby, on the Giza plateau, other architectural masterpieces stand up to the test of time: the sphinx, the lion with a human head, and the pyramids of Pharaohs Khafra and Menkaure. How and why are the two biggest pyramids in the world aligned? What secrets do these monuments still have to reveal?