LONDON, ENGLAND—After a decade of intense investigations at Stonehenge, archaeologists from University of College London now say that as many as 4,000 people gathered to construct the ancient monument, at a time when the total population of Britain was only in the tens of thousands. Their findings suggest that Stonehenge was not built as an observatory or an astronomical calendar, but rather may have been erected as part of a social ritual that brought together people from across the island. Analysis of animal teeth found nearby suggests that people came from as far away as Scotland to help build the monument. "What we have discovered is it's in building the thing that's important," says archaeologist Michael Parker Pearson. "It's not that they're coming to worship, they're coming to construct it."