"The Antikythera mechanism – a 2nd-century BC device known as the world's oldest computer – was discovered by sponge divers at the turn of the 20th century off a remote island in the Aegean.
The complex device of up to 40 bronze cogs and gears was used by the ancient Greeks to track the cycles of the solar system. It took another 1,500 years for an astrological clock of similar sophistication to be made in Europe."
http://www.theguardian.com/science/2014/sep/15/diving-suite-exosuit-worlds-oldest-computer-antikythera-mechanism