Antikythera mechanism is a complex clockwork mechanism that composed of at least 30 meshing bronze gears. It is often called the oldest computer (or an ancient analog Greek “computer”). The device could assist in predicting astronomical positions and eclipses and the Olympiads.
By just holding the device in hands, a user can track the paths of the Sun, Moon and planets with impressive accuracy.
Now using high-tech scanning, scientists are able to read Greek text inscribed on the device. The text is basically a user guide to assist the users. This is quite cool!