Labeled an “ancient Greek computer” sent from aliens (obviously), the Antikythera Mechanism was discovered in a deep sea ship wreck in 1900. It is able to accurately track the paths of the sun, moon, and planets, and nothing as technologically advanced shows up on the historical time line until some 1,000 years later. While there are small hints in reliable historical documents that have lead to a few key theories, the exact origin of the mechanism remains a mystery.