The Great Pyramid of Giza, built around 4,500 years ago, remains a mystery.

How was this 2.3-million-block, 6-million-ton marvel constructed? Theories range from ramps and lever systems to more outlandish ideas like aliens.

Ancient workers—not slaves—likely used sleds, water-lubricated sand, and sheer ingenuity. Despite centuries of study, its precise methods remain debated. Was it just manpower, or something more?