One widely recognized ancient Greek invention is the Antikythera mechanism. This device was found in a ship wreck off the small island of Antikythera, hence the name. No specific inventor is known. The mechanism was a type of calculator that was invented around 2000 years ago, between 150-100 B.C. It is considered the world's first computer, although it doesn’t resemble today’s computers. It had a complicated arrangement of gears, where there was a series of outer gears which rotated around a fixed central gear. The purpose of the mechanism was to determine the positions of the sun and the moon in relation to the known stars and planets, when a date was entered. The mechanism is one of the only creations that has no other inventions similar to it, until the clockwork gears of the 18th century. This invention shows how technologically advanced the Greeks were.