Overview: The Great Pyramid of Giza is the oldest and largest tomb ever built in Egypt, the most ambitious construction project of the ancient world, and one of history's greatest mysteries. How was it built by a Bronze Age society that only had simple hand tools at their disposal? Follow Egyptologist Mark Lehner and engineer Peter James as they attempt to solve this puzzle, armed with a radical new approach and a 4,500-year-old diary that gives an eyewitness account of the monument's construction.