2,100 yr-old Antikythera mechanism
"After a century of study, scientists have unlocked the secrets of a mysterious 2,100-year-old device known as the Antikythera mechanism, showing it to be a complex and uncannily accurate astronomical computer. The bronze-and-iron mechanism...could predict the positions of the sun and planets, show the location of the moon and even forecast eclipses. The international team of scientists reported today that the 1st century BC Greek device, the earliest known example of an arrangement of gear wheels, shows a technological sophistication that was not seen again until clockwork mechanisms were introduced in the 14th century. The results "imply that Greek technology was much more advanced in this area than was previously thought," said the team's leader, physicist Mike G. Edmunds of Cardiff University in Wales."
"If they could do this, what else could they do?" More.