A 4,000-year-old ritual monument has been discovered hidden in the Forest of Dean.
The Bronze Age ring cairn is made up of ten small standing stones on top of a raised bank in a woodland enclosure near Tidenham in Gloucestershire.
It is believed to be the only site of its type in the area, according to Jon Hoyle, an archaeologist working for the county council.
He first spotted the ring when examining the results of a survey of the forest using an airborne laser scan in 2006.
The technique uses a computer algorithm to strip away the trees and vegetation covering the forest floor to create a 3D impression of the surface.
It revealed a 25-metre-wide raised circle around a seven-metre-wide central mound, which Mr Hoyle initially thought may have been a gun emplacement from World War Two.
However, when he went to see the area for himself in 2010, he realised it could date back to around 2,000BC.
Of particular interest were the one-metre-high standing stones protruding from the ring, consistent with early or middle Bronze Age ring cairns found in Wales.
“Nobody knows precisely what they were used for,” Mr Hoyle told the BBC. “Some have been found in association with burials, and often there appear to be residues of charcoal in places like this, suggesting rituals that involved fire.”
The same survey also uncovered more than 100 possible burial mounds which have not yet been properly investigated.
Another Bronze Age monument, a round cairn burial mound made up of limestone slabs, was found in nearby Tidenham Chase in the 1960s.
Mr Hoyle published details of his discovery in a book for Historic England, Hidden Landscapes of the Forest of Dean, last month.
