When it comes to ancient Earth, there are more than a few mysteries that leave us scratching our heads. While it's likely that the pyramids in Egypt, for example, were built by humans, there always seems to be the possibility that there were other forces at work.
Another ancient mystery that's missing a good answer is that of these massive, ancient geoglyphs that have been found in mountains and deserts. It seems unlikely that these were created by ancient man. Perhaps there's a more paranormal explanation...
From the Middle East to South America, there are ancient geoglyphs in too many places for them to be a coincidence. Until very recently, the oldest geoglyphs were thought to be the South American Nazca Lines (pictured below).
However, researchers now believe that they've uncovered new evidence that the Nazca Lines are only the second oldest geoglyphs in the world.
This week, researchers working to decode geoglyphs in the Middle East discovered that several of the massive creations predate the Nazca Lines by at least a few hundred years.
While this new information doesn't exactly shed light on who built them, it does deepen the mystery of their existence.
Some of the ancient tribes who still travel the deserts of Saudi Arabia call these creations "the works of old men."
(via Live Science)
So...who the heck built these things? That's the million-dollar question.