How Far Did Neolithic Britons Carry Stonehenge’s Most Famous Boulder?
In a find that provides insights into the remarkable abilities of these ancient humans, new research studying the chemical footprint of the rock identified the source to be more than 400 miles away
Lying on the ground near the center of Stonehenge, partially covered by two huge slabs that appear to have toppled over, is a 16-foot-long block of gray-green sandstone. In 1620, noted landscape architect Inigo Jones suggested that it might have been used as an altar, and it has been known as the Altar Stone ever since. Weighing six and a half tons and transported to the monument around 5,000 years ago, it was long thought to have come from south Wales.
But recently, a team of researchers, by analyzing the chemical fingerprint of the rock, found out that the Altar Stone almost certainly came from the Orcadian Basin in northeast Scotland. It was an astounding discovery, because it meant the megalith must have traveled at least 465 miles to Salisbury Plain.
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How did Neolithic Britons undertake such an epic feat of transportation? In a paper published this past December in Archaeology International, the researchers suggest possible methods and routes. The stone might have been dragged overland on a “suitably robust wooden sledge with vegetation-made shock absorbers,” sliding on movable wooden rails. That hypothetical journey would have faced formidable obstacles including mountains, rivers and dense forests, and may have taken about eight months. The other possibility is that this massive cargo was transported by boat along the coast. Neolithic Britons had maritime trade routes for cattle and heavy stone-grinding tools. Perhaps their vessels could even have floated a 13,000-pound megalith.
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Why did they move the Altar Stone such an immense distance? To answer the question, researchers focused on a unique aspect of the site: Of the 900-plus prehistoric stone circles in Britain, it is the only one that was built entirely from non-local stones. The Altar Stone seems to have traveled the greatest distance, but the bluestones—turquoise in the diagram on the left—were quarried 140 miles away, in Wales, and even the nearest stones were dragged 14 miles. The researchers therefore hypothesize that Stonehenge was an effort to bring together far-flung communities on the island, by building with the most magnificent rocks from each. The Altar Stone might have represented an alliance between the Neolithic Britons who built Stonehenge and people in northern Scotland.
Based on these new insights, lead author Mike Parker Pearson, an archaeologist at University College London and a renowned expert on Stonehenge, has described the site as “a monument of unification for the peoples of Britain, celebrating their eternal links with their ancestors and the cosmos.” Based on these new insights, lead author Mike Parker Pearson, an archaeologist at University College London and a renowned expert on Stonehenge, has described the site as “a monument of unification for the peoples of Britain, celebrating their eternal links with their ancestors and the cosmos.”
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This article is a selection from the April/May 2025 issue of Smithsonian magazine