Steeped in mystery, Stonehenge -- a megalithic monument dating back to 2,800 B.C. -- stands on Salisbury Plain in England's Wiltshire County. Using location footage, 3-D computer graphics, meticulous reconstructions and insightful analysis, this fascinating documentary investigates the story behind the intriguing structure, including the myths and realities surrounding the ancient stone circle that continues to bewilder experts.