London - England has opened public access to a little-known neolithic complex of huge circular earthworks seen as rivalling Stonehenge in importance, after the site's owners gave it to the nation.
Thornborough Henges in Yorkshire, northern England, were not previously accessible to the public and featured on a list of heritage sites at risk.
English Heritage, a charity that cares for state-owned historic sites and monuments, called the site the "Stonehenge of the North" as it opened free public access on Friday.
“We are thrilled to have acquired this highly significant site for the nation, ensuring that these magnificent monuments are safe and will be preserved for generations to come,” said Duncan Wilson, the chief executive of Historic England, the public body responsible for historic monuments.
The site is made up of three henges, or giant circular earthworks more than 200m in diameter.
Standing on moorland, they are believed to have been built for ceremonies and rituals in the period between 3500 and 2500 BC.
This potentially makes the site older than Stonehenge, dating from around 2500 BC, which also features henges. Both were built before Britons had metal tools.
The earthworks at Thornborough might originally have been covered with a mineral, called gypsum, and glowed white, English Heritage said.
Still visible today are circular banks up to 4m high and encircling ditches.
Two of the henges were given to the nation by Tarmac group, a road-building company that owned the land.
The third henge is in private ownership and under woodland.
The henges were added to Historic England’s at-risk register in 2009, due to erosion from farm animals and rabbits grazing. They aredue to be removed from the register.
Stonehenge standing stone circle in south-western England is one of the UK’s best-known tourist attractions, with more than 330 000 visitors in 2021.