"The Antikythera mechanism is an ancient analog computer designed to predict astronomical positions and eclipses for calendrical and astrological purposes, as well as the cycles of Olympic Games."
"The artifact was recovered in 1900–1901 from the Antikythera shipwreck off the Greek island of Antikythera. Believed to have been designed and constructed by Greek scientists, the instrument has been dated either between 150 to 100 BC or, according to a more recent view, at 205 BC.
After the knowledge of this technology was lost at some point in Antiquity, technological artifacts approaching its complexity and workmanship did not appear again in Europe until the development of mechanical astronomical clocks in the fourteenth century."
"Generally referred to as the first known analog computer, the quality and complexity of the mechanism' manufacture suggests it has undiscovered predecessors made during the Hellenistic period. Its construction relied upon theories of astronomy and mathematics developed by Greek astronomers, and is estimated to have been created around the late second century BC."
