Stonehenge isn't the oldest monument of its kind in England, study reveals

A Stone Age circular monument in England is even older than Stonehenge, raising the possibility that Stonehenge's creators used it as inspiration, a new study finds.

When researchers radiocarbon-dated artifacts from the large monument, known as Flagstones, they found that it dates to about 3200 B.C. — meaning it's about 200 years older than Stonehenge. Previously, archaeologists thought Flagstones was the same age as the earliest stages of Stonehenge, which was built and reconfigured over the centuries. The researchers published their findings March 6 in the journal Antiquity.

The discovery "makes Flagstones the earliest large circular enclosure known in Britain," said study first author Susan Greaney, a lecturer in archaeology at the University of Exeter in the U.K. "It might be that Flagstones was copied at Stonehenge, or it might be that we need to go back to our dates of Stonehenge and think again," she told Live Science in an email.

Flagstones, an ancient monument and burial site, was found in the 1980s during construction of the Dorchester bypass in Dorset, a county in southwest England. Excavations unearthed a 330-foot-wide (100 meters) circular ditch that was made with intersecting pits. The pits have at least four sets of human remains: a cremated adult and three children whose bodies were buried there. The partially cremated remains of three other adults are located elsewhere at the site, according to a statement from the University of Exeter.

Now, half of the monument is under the bypass, while the other half is under a historical home managed by the National Trust, a conservation organization. The site's artifacts are housed at the Dorset Museum.

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Flagstones is about 37 miles (60 kilometers) southwest of Stonehenge. Its similarity to the early stages of Stonehenge, which also includes cremated burials and a similarly sized enclosure made of intersecting pits, led archaeologists to think the two were built at the same time, around 2900 B.C. But as part of her doctoral research, Greaney put together a more detailed timeline of a cluster of Neolithic monuments in the Dorchester area whose artifacts are kept at the Dorset Museum.

"With new techniques for obtaining precise radiocarbon dates, and advanced statistical methods, we can now obtain really precise estimates for when events like monument construction took place," Greaney said.

To more accurately date Flagstones, Greaney and her colleagues radiocarbon-dated human remains, red deer antlers and charcoal found at the site. By combining these dates with those of archaeological finds from the site, Greaney and her colleagues estimated that the pits were dug around 3650 B.C. but that the circular enclosure wasn't formed until 3200 B.C. and the burials were placed there soon after. A young adult male who was buried under a large sarsen stone at the center of the Flagstones' enclosure was placed there much later — around 1,000 years after the monument was first used.

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The ancient antler of a red deer that was found at Flagstones.

A bird's-eye view of excavations at the Flagstones monument in Dorset, England.

A new type of monument

At 5,200 years old, Flagstones is the oldest known large, circular enclosure of its kind in Britain. After its construction, circular monuments were built in numerous other locations.

"It is part of a shift from predominantly rectangular or linear monuments (cursus monuments, long barrows) or irregular enclosures (causewayed enclosures) towards circular forms," Greaney said.

The new study suggests that circular monuments like Flagstones "may have been influenced by practices in Ireland, where people were burying their cremated dead in circular passage tombs at this time," she said.

Although the new dates suggest that Flagstones is older than Stonehenge, Greaney thinks that scientists should reassess and redate Stonehenge. After all, some of Stonehenge's artifacts are thought to be older than the site itself.

"There are some 'curated' animal bones from near the entrances to the enclosure at Stonehenge, which do date from around 3200 BC," Greaney said. "It's been assumed that these deer bones and cattle skulls had been kept for some time before being deposited in the ditch.

"With the new dates from Flagstones, it's now possible to look at these deposits, which were in slightly deeper parts of the ditch, and ask whether there was an earlier enclosure made up of intercutting pits which only later people joined together to form the more continuous ditch, which happened in c. [circa] 2900 BC," Greaney added.

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