Holy crap, the Antikythera Mechanism.
This was an ancient Greek computer - yes, computer - likely designed by Archimedes himself for predicting the movements of the heavenly bodies. Later refined and miniaturized over the centuries, fragments of a portable 1st century BCE version of the device were found in the Antikythera shipwreck at the dawn of the 20th century, but only properly understood much more recently thanks to advances in X-Ray and computer imaging.
The relationships between the thirty astronomically boggling gears are intricate and incredible; predicting the shifting elliptical movements of the moon and planets with absolute precision. The mechanism has correctly predicted the days, hours, and colors of lunar eclipses that have occurred in a sky thousands of years beyond its own creation.
These digital recreations are the dedicated work of Tony Freeth, a mathematician/filmmaker at the forefront of the Antikythera Mechanism Research Project.