The Antikythera mechanism is an early form of analogue computer used for astronomy. It was discovered in the early 20th century and is considered extremely advanced. Dating has placed the mechanism around the 1st century BC and similar levels of technology were not seen again until the 14th century.
Researchers are unsure of the mechanism’s origins and speculate that it may be from a Corinthian colony such as Syracuse or was perhaps from a city further east such as Pergamon in modern day Anatolia.
The mechanism was discovered on a shipwreck and a great deal of mystery surrounds it and it’s origins. One theory is that it was lost when being transported to Rome for the triumph of Julius Caesar. Whatever the case may be, it is an intriguing artefact and a great example of Hellenistic technology and engineering.