New research has overturned a century-old belief about the origins of Stonehenge’s famous Altar Stone. The new study shows that the six-tonne sandstone block, which forms the centerpiece of the ancient monument in southern England, actually hails from Scotland, not Wales as previously thought.

Through detailed analysis of the mineral grains within the Altar Stone, the scientists were able to create a chemical “fingerprint” that matches rocks found in the Orcadian Basin of northeast Scotland, over 750 kilometers from its final resting place at Stonehenge, on Salisbury Plain.

A Monumental Discovery

While most visitors to Stonehenge admire the structure from a distance, few are aware of the Altar Stone lying beneath a pile of collapsed stones at the center of the monument. The stone, first identified by the architect Inigo Jones in 1620, has been the subject of debate for centuries. Was it ever standing upright, or has it always been recumbent? The exact position of this 6-ton sandstone remains a mystery, with experts divided over its original placement.

Over the years, the Altar Stone has been overshadowed by the more prominent features of Stonehenge, such as the towering sarsens and the enigmatic bluestones. However, its story is no less compelling. The stone is partially buried under what is known as the Great Trilithon, a major feature of the megalithic site that collapsed at an unknown point in history. This collapse, which may have occurred between the Neolithic and early modern periods, has left the Altar Stone in two halves, largely hidden from public view.

For years, the 16-foot Altar Stone was grouped with the so-called “bluestones” of Stonehenge, many of which are believed to have been sourced from the Preseli Hills in Wales. The new findings, however, suggest a different story.

By examining the age and chemical composition of tiny grains of zircon, apatite, and rutile, the team traced the stone’s geological fingerprint back to the Orcadian Basin. This region, known for a specific type of sandstone formation, provided a near-perfect match with the Altar Stone, suggesting a Scottish origin.

“This discovery rewrites what we know about Stonehenge,” said Anthony Clarke, lead author and PhD student at Curtin University. “It raises fascinating questions about how such a massive stone was transported over such a vast distance, considering the technological constraints of the Neolithic era.”

Positioned centrally, the stone is thought to have been a key feature in the Stonehenge layout, around which other stones were arranged. Its specific placement and orientation suggest it may have held significant symbolic or religious meaning for the Neolithic people who constructed Stonehenge, although the exact rituals associated with Altar Stone remain unclear.

However, the implications of this discovery extend beyond the Altar Stone itself. The findings suggest a much more sophisticated level of societal organization and long-distance connectivity in Neolithic Britain than previously understood. Transporting a six-tonne stone across hundreds of kilometers would have required not only advanced planning and coordination but also significant knowledge of marine and land-based transportation methods.

“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 around 2600 BCE,” Clarke said.

Researchers believe that the stone was likely transported by sea, navigating along Britain’s coastline before making its way inland to Stonehenge. Another alternative proposed a few years ago by geologists Rob Ixer and Richard Bevins proposes a different scenario. Their findings suggest the stone may have been transported overland, following a route bypassing hazardous coastal currents and cliffs.

“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,” said Professor Chris Kirkland, co-author of the study.

“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.”

Rethinking Neolithic Britain

The study also opens the door to new questions. Why was the Altar Stone brought from such a distant location? What role did it play in the construction and significance of Stonehenge? While the research provides crucial new information, it also leaves many mysteries about the monument’s history and purpose.

The team’s work builds on previous studies that began to cast doubt on the Altar Stone’s Welsh origins. The latest findings, however, provide the strongest evidence yet that this central piece of Stonehenge’s structure has its roots far to the north.

As researchers continue to probe the origins and journey of the Altar Stone, this discovery is likely to spur further investigations into the connections between ancient communities across Britain and the methods they used to construct one of the world’s most iconic monuments.

“While we can now say that this iconic rock is Scottish and not Welsh, the hunt will still very much be on to pin down where exactly in the north-east of Scotland the Altar Stone came from,” said Co-author Professor Richard Bevins from Aberystwyth University.

With these findings, Stonehenge remains not just a marvel of ancient engineering, but also a testament to the complex and far-reaching networks of Neolithic societies.

“This discovery also holds personal significance for me. I grew up in the Mynydd Preseli, Wales, where some of Stonehenge’s stones came from. I first visited Stonehenge when I was one year old and now at 25, I returned from Australia to help make this scientific discovery – you could say I’ve come full circle at the stone circle,” Clarke said.

The new findings appeared in the journal Nature.