10 ancient mysteries researchers still can’t explain

The 2,000-year-old Antikythera mechanism found in an ancient Greek shipwreck has been dubbed the “first computer,” using a wind-up dial system to track celestial time of the Sun, Moon, and five planets, along with a calendar, the phase of the Moon, and the timing of eclipses.

It was more sophisticated than any other tool that would be invented for the next 1,000 years, which sparked theories that it must have come from aliens.

While most researchers don’t stand behind that theory, they still aren’t sure how the Greeks managed to create a tool so much more advanced than anything we’ve seen of that era.

Sound creepy? Check out these 12 spooky Ouija board stories that will give you chills.