Stonehenge’s Massive Central Stone May Have Been Shipped From Hundreds of Miles Away

For many years, historians thought the Altar Stone at the center of Stonehenge, England’s famed prehistoric monument, came from Wales. However, new research suggests its journey was much longer.

According to a study published this week in the journal Nature, the stone may have traveled all the way from Scotland—meaning that builders transported it across more than 400 miles some 5,000 years ago.

“Given its Scottish origins, the findings raise fascinating questions, considering the technological constraints of the Neolithic era, as to how such a massive stone was transported over vast distances,” says lead author Anthony Clarke, a geologist at Curtin University in Australia, in a statement from the university.

The Altar Stone lies partially buried within Stonehenge’s horseshoe. It’s stationed beneath two other stones from a fallen trilithon (a formation of two standing rocks capped by a shorter horizontal rock). For many years, the central stone has been an “anomaly, lying recumbent in what should be the most sacred bit of space inside the monument,” as Joshua Pollard, an archaeologist at England’s University of Southampton who was not involved in the research, tells CNN’s Ashley Strickland.

Now, the Altar Stone’s story has become even stranger. After analyzing the stone’s chemical makeup, the researchers determined that certain mineral grains were between one and two billion years old, while others were roughly 450 million years old.

“This provides a distinct chemical fingerprint suggesting the stone came from rocks in the Orcadian Basin, Scotland, at least 750 kilometers [466 miles] away from Stonehenge,” Clarke says in the statement.

Stonehenge was constructed in phases, beginning around 3000 B.C.E. Today, the monument is “the most architecturally sophisticated and only surviving lintelled stone circle in the world,” per English Heritage, which manages Stonehenge and other British historical sites. Researchers think builders placed the 13,200-pound Altar Stone at the monument sometime between 2620 and 2480 B.C.E.

“The Altar Stone was always grouped with the other bluestones, which are the smaller stones in the ring,” co-author Nick Pearce, a geological chemist at Wales’ Aberystwyth University, tells Live Science’s Jennifer Nalewicki. “It was long believed the bluestones could only be found in southern parts of the U.K., such as South Wales. After examining the mineralogy of the stones, it didn’t add up that the Altar Stone was from Wales.”

Nobody knows how the builders transported the stone. According to the researchers, Neolithic communities did use Britain’s waterways to transport goods and cattle, and one large stone grinding tool apparently traveled from Normandy to Dorset. Therefore, it’s plausible that stone cargo could have been shipped over open water during Stonehenge’s construction.

“Transporting such massive cargo overland from Scotland to southern England would have been extremely challenging, indicating a likely marine shipping route along the coast of Britain,” says study co-author Chris Kirkland, a geologist at Curtin University, in the statement. “This implies long-distance trade networks and a higher level of societal organization than is widely understood to have existed during the Neolithic period in Britain.”

Archaeologist Mike Pitts, author of How to Build Stonehenge, who wasn’t involved in the research, thinks a land journey is also plausible.

“If you put a stone on a boat out to sea, not only do you risk losing the stone—but also nobody can see it,” Pitts tells the Guardian’s Esther Addley. On land, many communities would witness the journey, and the stone would become “increasingly precious … as it travels south.”

Pitts adds that the study is “so significant” because it shows that groups communicated across vast distances, suggesting that Stonehenge “was known not just to people in the south, but over a much wider area.”

Sonja Anderson | READ MORE

Sonja Anderson is a writer and reporter based in New York City.