It is known as Antikythera Mechanism, and is believed to be world’s oldest computer which has been described as astronomical calculator as well as the world’s first analogue computer. It is unique Greek geared device and is believed to be constructed around the end of the 2nd Century BC.   It is made of bronze and includes dozens of gears. It is hand-powered mechanical device and was used for calculation and displaying information about astronomical Phenomena specially the positions of the Sun, Moon and the planets and lunar and solar eclipses decades in advance. It had front and back doors, with astronomical inscription covering much of the exterior of the Mechanism. All known fragments of the Antikythera Mechanism are now housed in the National Archaeological Museum in Athens, along with numerous artistic reconstruction and reproduction to demonstrate how it looked and worked.

Also Referred As : Oldest computer, World’s first computer, Ancient Greek computer, Antikythera mechanism, Ancient astronomical computer, Ancient hand-powered computer, Ancient mechanical computer.