Since the beginning of time, we have counted on science and archeology to learn more about ourselves and our world. We’ve only been around for a fraction of the Earth’s age so we’re left to pick up pieces of our distant history. So far, we’ve done a pretty good job. From what we’ve found, we’ve been able to tell a story of our world. However, once in a while, we discover strange things that question everything we know. From ancient giants who lived in the Americas to alien pharaohs who ruled ancient Egypt, here are 10 of the most controversial discoveries.