The handful of examples they eventually discovered of the distinctive "cup mark" art, a motif of circular hollows within hollows, could be dated only very broadly at between 3800 and 2000 B.C. "We didn't get anything we could confidently put in for dating," Darvill said. This much, however, is known: Perhaps as early as 4000 B.C., people were constructing monuments in this atmospheric area where rock pinnacles seem to pierce the sky and commemorating the site with motifs associated elsewhere with "special" sites. "In Neolithic times people are going to the Preseli hills and venerating them," was how one archaeologist put it.

Whether the stones were moved to Salisbury Plain in a single, sustained campaign or an ongoing effort spread out over a generation or more is not known. Similarly, how the stones were transported has been hotly debated over the years. "That's a blue-collar question," Wainwright said, relishing what was clearly a well-rehearsed line, "and I am not an engineer." Although glacial drift may initially have worked the stones loose from the hills, an old theory that glaciers swept them onto Salisbury Plain has been discounted by modern studies; somehow people must have moved them. The shortest accepted route—by river and along the coast of Wales, across the Severn estuary, into the upper reaches of the Avon—is about 250 miles. It is impossible to judge just how remarkable a feat such transport was in its day. As Darvill points out, in continental Europe even more massive stones were being lugged around. "Increasingly, the 'unaccountable effort' argument is under attack," Darvill said. "The Grand Menhir in Brittany—what does it weigh? Three hundred and forty tons, something like that, and it was moved at least a few miles." Whether the stones were pulled by teams of men or oxen, on sleds with greased tracks, giant rollers of wood, or some other unsuspected means, Neolithic man evidently, as Darvill said, "had transportation sorted out."

Archaeologists can only speculate about the significance of the bluestones. Carn Menyn may have been a landmark charged with special meaning in a key overland route for trade or travel. Some claim the arrangement of the types of bluestone—dolerite, rhyolite, and tuff—at Stonehenge mirrors their natural arrangement on Carn Menyn. Then again, perhaps the very effort of transporting the stones or their exotic nature was the point&#mdash;a kind of statement of ability and power.

Darvill and Wainwright believe the answer lies in an old tradition. Writing in the 12th century A.D., Geoffrey of Monmouth, in his rambling, gossipy meander through the history of the kings of Britain, gave a fanciful account of how Stonehenge was carried bodily—on the orders of the wizard Merlin, no less—from Ireland to Salisbury Plain, where it was set down to be a place of healing. The story may represent oddments of tenaciously preserved folk memory garbled by a long—in this case, 3,600-year-old-oral tradition; the stones of Stonehenge were, after all, brought from a far place in the west by seemingly magical means.