No place has generated so much speculation and wild theories as the standing stones of Stonehenge. After driving for miles through the rolling hills and plains of the English countryside the sight of this unusual structure makes people gasp. A walk around it only provokes more strange feelings. There's a sense that this is something very important. It taunts us with its mystery. For over 5000 years it has stood silent vigil over the earth. It has been excavated, x-rayed, measured, and surveyed. Yet despite all that has been learned about its age and construction, its purpose still remains one of the great mysteries of the world.
another documentary: "Stonehenge Decoded" (National Geographic)