History's Greatest Mysteries: Season 4, Episode 16 - ProjectFreeTV

4 - 16: Unlocking the Secrets of Stonehedge

It's one of the most famous prehistoric monuments on Earth. A mysterious arrangement of stones that have adorned the English countryside for millennia. But to this day, nobody knows how the landmark was built or why. Can modern technology finally unlock its secrets? What is the true purpose of Stonehenge?