Volunteers Uncover Rare, 4,800-Year-Old Stone Circle in England

Ground scans at Castilly Henge revealed seven pits where ancient stones once stood

Aerial view of Castilly Henge in Cornwall, England
The Neolithic-Era henge was completely obscured by overgrown vegetation.  Heritage England

Ring-shaped henges dot the English countryside—and have stumped archaeologists for years. What were they used for? Did they serve as religious sites or have some more mundane purpose?

Now, the discovery of a rare stone circle at a prehistoric henge in Cornwall is raising the same old questions—and deepening researchers’ understanding of these iconic sites. The Guardian’s Harriet Sherwood reports that conservation efforts by the government commission Historic England revealed pits in a “crooked horseshoe formation” at Castilly Henge.

Research at the Late Neolithic henge began in 2021 after overgrown vegetation was removed from the site to allow researchers to get a closer look. According to the BBC News, scientists using ground-penetrating radar and other techniques discovered a previously unseen circle with seven points where stones would have been.

There could be more of the regularly-spaced pits which, when combined with the others, might form a complete oval. However, scientists were unable to sufficiently examine the northern area of the site due to ground conditions. Based on the pits they did find, researchers believe some of the stones were eventually removed and taken away, while others would were pushed face-down into their own pits.

In a statement, Cornwall Archaeological Unit senior archaeologist Peter Dudley, said that 13 volunteers gave 111 hours of their time to clear the bracken and scrub that obscured the henge. “Now the monument is looking so much better,” says Dudley.

The oval-shaped henge is 225 feet long and 205 feet wide and has been dated to the late Neolithic period, around 2,700 B.C.E. At that point in British history, the isle’s inhabitants had mastered farming grains and were starting to flesh out their cultures. Using flint for their weapons and tools, they built monuments like henges and established burial rituals.

Though they’re unclear on the specifics of those rituals, experts think henges served as sites for gathering or ritual purposes. In more recent years, the Guardian reports, it’s possible Castilly Henge was used as a theater in the Middle Ages and as a weapons nest during the English Civil War.

Per English Heritage’s website, fewer than 100 of the henges of Britain and Ireland survive today, “although it’s very likely there were originally more.” The agency writes that the Neolithic and Bronze-Age henges are generally between 65 and 330 feet wide and are characterized by ring-shaped outer banks and inner ditches.

Henges with stones are rarer still. Among them are the Stripple Stones in Cornwall and the famous Stonehenge in Wiltshire (though archaeologists argue it isn’t technically a henge since its ditch lies outside its bank).

One of the great wonders of the ancient world is the fact that, in an era before motor vehicles or modern tools, prehistoric individuals nonetheless managed to get the massive stones, known as megaliths, into position to create the stone rings. In the case of Stonehenge, some of the stones weigh up to 40 tons and would have been transported from local sources up to 30 miles away. Modern scientists believe ancient peoples would have moved these stones via sleds—perhaps greased with lard and mounted on rollers or rails. Moving a single stone could have required as many as 150 people.

Historic England is committed to repairing and conserving the thousands of places on its at-risk historic register, among them over 2,000 archaeological sites. Now that Castilly Henge is no longer covered with overgrowth, the agency says in the statement, it is visible once more. The addition of a fence on the site will also allow the farmer who owns the land it’s on to graze his animals again.

“The research at Castilly Henge has given us a deeper understanding of the complexity of this site and its importance to Cornish history over thousands of years,” Ann Preston-Jones, a project officer for at-risk heritage sites with Historic England, says in the statement. “It will help us make decisions about the way the monument is managed and presented, so that it can be enjoyed by generations to come.”