The Antikythera Mechanism is an ancient Greek astronomical device that was discovered in 1901 in the Antikythera wreck off the coast of the Greek island of Antikythera. It is believed to have been constructed in the late 2nd century BC and is considered to be
From Wikipedia
The Antikythera mechanism is an ancient Greek hand-powered orrery. It is the oldest known example of an analogue computer. It could be used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games similar to an olympiad, the cycle of the ancient Olympic Games.