Johnno
The Living Force
There's a video on youtube I just came across with a guy building his own form of Stonehange using levers, pivot points, buckets of sand and such......all by himself. Not sure if it how they built Stonhenge or not but it's rather interesting from a simple engineering perspective.
http://www.youtube.com/watch?v=lRRDzFROMx0
http://www.youtube.com/watch?v=lRRDzFROMx0