The Antikythera Mechanism is an ancient Greek device, believed to have been constructed around 150-100 BC, that is considered to be the world's first analog computer. It was discovered in the Antikythera wreck off the Greek island of Antikythera in 1901 and
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.