of the Khafre Pyramid in the background then light up the Sphinx itself. Converging Pyramids The Pyramids were not laid out willy-nilly on the Giza Plateau. Each side of each of the three Pyramids lines up precisely east-west or north-south. It's a bit of a mystery how the ancients achieved such a perfect alignment, considering they did not have the magnetic compass at their disposal. The Pyramids' proportions are just as exacting. For example, the greatest difference in the length of the Great Pyramid's four sides at its base, which are about 750 feet long, is less than two inches. As you scroll along this image, which was shot from the desert a few miles south of the Pyramids, notice how the three structures -- those of Menkaure, his father Khafre, and his grandfather Khufu -- eventually line up perfectly along their righthand edges. PHOTO GALLERIES: Khufu 1 The Great Pyramid of Khufu contains about 2,300,000 blocks of stone. Until the early 20th century, it was the tallest building in the world. Khufu 2 Visitors clamber -- illegally -- on Khufu's Pyramid. Khufu 3 Ancient Egyptians built the Solar Barque of Khufu in the 26th century B.C., then buried it in pieces within a carved stone pit directly beneath the Great Pyramid. After it was discovered in 1954, the vessel was reassembled and installed in its own museum next to the pyramid. Khufu 4 Was Khufu's body taken across the Nile in this cabin 4,600 years ago? Khufu 5 Fully