For all we know about ancient history, there’s still a lot of knowledge which we haven’t yet obtained, and may never obtain. A lot of our ancestors took their secrets to their graves, leaving us to guess and what they meant by their customs, rituals, and architectural works all these years later. Without better explanations being available, some of the items you’re about to see in this video are claimed to have paranormal or extraterrestrial origins. Some have been hidden under the ground, but others hide in plain sight!