The Antikythera Mechanism: http://bit.ly/fm4oFK is the oldest known scientific computer, built in Greece at around 100 BCE. Lost for 2000 years, it was recovered from a shipwreck in 1901. But not until a century later was its purpose understood: an astronomical clock that determines the positions of celestial bodies with extraordinary precision. 

In 2010, we built a fully-functional replica out of Lego. 

Sponsored by Digital Science: http://www.digital-science.com/ a new division of Macmillan Publishers that provides technology solutions for researchers. Available under a CC-BY-3.0-Unported license.

http://hackaday.com/2010/12/09/lego-machine-predicts-future-eclipses/