Archaeological research conducted on a prehistoric burial site has shown that it is the earliest known large circular enclosure in Britain.
The Flagstones monument, near Dorchester in Dorset, has been redated to about 3,200 years BC, approximately two centuries earlier than previously thought.
Archaeologists have used advanced radiocarbon analysis to examine some of the finds, including human remains, red deer antlers and charcoal.
An aerial view of the original excavation site (Dorset Museum/PA)
The analysis, conducted by the University of Exeter and Historic England, suggests that Flagstones may have served as a prototype for later monuments like Stonehenge.
“Flagstones is an unusual monument, a perfectly circular ditched enclosure, with burials and cremations associated with it,” said Dr Susan Greaney, from the University of Exeter.
“In some respects it looks like monuments that come earlier, which we call causewayed enclosures, and in others it looks a bit like things that come later that we call henges.
“But we didn’t know where it sat between these types of monuments and the revised chronology places it in an earlier period than we expected.”
Flagstones was discovered in the 1980s during the construction of the Dorchester by-pass, and excavations showed it was formed of a 100m diameter circular ditch made of intersecting pits, probably an earthwork bank.
Today half of the site lies beneath the by-pass, with the remainder beneath Max Gate, Thomas Hardy’s former home, now bequeathed to the National Trust.
Flagstones is a scheduled monument with finds and excavation archives preserved at Dorset Museum.
At least four burials were found to have been placed in the enclosure pits, a cremated adult and three children who had not been cremated, and there were three partial cremations of adults elsewhere.
The similarity of this site to the first phase of Stonehenge, dated to about 2900 BC, led to the assumption that Flagstones must be of a similar date.
An excavated red deer antler, which was one of the items analysed for the new research (Dorset Museum/PA)
The new findings suggest the early Neolithic activity, including the digging of pits, took place in about 3650 BC.
After a gap of many centuries, the circular ditched enclosure was created in about 3200 BC, with burials placed within it immediately afterwards.
A later burial of a young adult male under a large sarsen stone at the centre of the enclosure took place about 1,000 years or so after its initial use.
“The chronology of Flagstones is essential for understanding the changing sequence of ceremonial and funeral monuments in Britain,” said Dr Greaney.
“The ‘sister’ monument to Flagstones is Stonehenge, whose first phase is almost identical, but it dates to around 2900 BC.
“Could Stonehenge have been a copy of Flagstones? Or do these findings suggest our current dating of Stonehenge might need revision?”
Flagstones also shows connections to other significant sites, including at Llandegai in Gwynedd.
– The study, Beginning of the circle? Revised chronologies for Flagstones and Alington Avenue, Dorchester, Dorset, is published in the journal Antiquity.