Archaeologists Have Made An Incredible Discovery At Stonehenge. Using powerful ground-penetrating radar, investigators have detected burial mounds, chapels, shrines, pits — and most remarkable of all — a massive megalithic monument made up of more than 50 giant stones buried along a 1,082-foot-long c-shaped enclosure. This changes virtually everything we thought we knew about Stonehenge. The news comes just a week after finding out that Stonehenge was once a complete circle . Sept. 10, 2014