2000-year-old computer recreated

The device was discovered more than a century ago by sponge divers from the Aegean island of Symi. It was a hand-wound clockwork device used to calculate the motions of the sun, moon and planets as seen from Earth, as well as to predict solar and lunar eclipses.
The complexity of the design, and the fact that it incorporated state-of-the-art astronomical knowledge, suggest that the maker cared a great deal about the accuracy of the mechanism.