A very mysterious object that turned history upside down is the so-called Antikythera Mechanism. It is a sort of clock that is now housed in the Greek National Archaeological Museum in Athens. This clock was found in 1900 – 1901 by sponge divers near the tiny island of Antikythera, between Greece and Crete. The wreck where this object was found sank around 65 BC.
What makes it so mysterious is that the mechanical technology, and the purpose of the object, is typical of 18th century technology – not BC technology!
All the metal parts of the machine seem to have been cut from a single sheet of low-tin bronze about two millimetres thick; no parts were cast or made of a different metal. From the ancient Greek inscriptions on the plate of the clock, we can assume that it dates from the first century BC. It was designed for use in astronomy and served to calculate sunrise, sunset and moon movements. This all means that more than 2000 years ago, the Greeks – or someone who expressed himself in the old-Greek language - were already using technology which we only invented 300 years ago.

Moreover, there is no other clock that resembles the Antikythera Mechanism which is strange. Not even simpler clocks. If it was common technology in the first century BC, why then were no similar devices found? It must have been very important technology for the ancient Greeks and Romans . But there is no sign that they possessed this technology. Since the ship that carried this artefact was on its way from Rhodes and Cos, and was wrecked around Antikythera; one might guess that is was heading for Rome. Had it arrived, it would certainly have increased the dominance of that world power.
So, the question is: who was able to create such a complex machine, without any preceding development of knowledge?
For a detailed discourse, see ref. Sola Price.