Three huge ancient monuments known as “Stonehenge of the North” are to be opened to the public.
Historic England and English Heritage said they have secured the future of Thornborough Henges following a deal with construction firm Tarmac.
English Heritage will take over and open the site near Ripon, North Yorkshire, to the public from Friday.
The Neolithic site consists of three circular earthworks – or henges – which are more than 200 yards in diameter and date from 3500 to 2500 BC.
Historic England said they are “unparalleled in their size, alignment and degree of preservation”.
Chief Executive Duncan Wilson said: “Thornborough Henges and the surrounding landscape form part of the most important concentration of Neolithic monuments in Northern England.
“They are a link to our ancient ancestors, through thousands of years, that inspire a sense of wonder and mystery.
“We are delighted to have acquired this extremely important site for the nation, ensuring that these magnificent monuments are safe and preserved for future generations.”
Prime Minister Rishi Sunak, who is a local MP, said: “The Thornborough Henges site has enormous potential to tell the story of ancient Britain and I very much welcome this announcement about its future – to protect and preserve it for the nation.
“Few people are aware of its importance – locally and nationally. I hope that many more will come to appreciate this little-known gem of our history and, in doing so, provide a boost to the local visitor economy.”
Historic England said that the Thornborough Henges are located in an ancient, ritually prehistoric landscape that stretches from Harbor Bridge to Catterick and are “unparalleled in size, alignment and degree of preservation”.
Like Stonehenge, the enormous amount of power put into their construction is considered a reflection of their importance to the society that created them.
The evidence suggested that they may have been covered with minerals that would have made them glow and would have been visible for miles around.
Archaeologists have suggested that the heirs were probably built as ceremonial or ceremonial centers and that they may also have been trading centers and meeting places.
Today the three henges are clearly visible as huge circular banks, up to four meters high, surrounded by ditches of varying depths.
The central and southern henges are actively farmed and are therefore not as well preserved as the northern henge, which is still privately owned.
The two southernmost henges were added to Historic England’s Heritage in Danger Register in 2009 and Historic England is working with Tarmac to secure their future.
Stuart Wykes, director of land and natural resources at Tarmac, said: “Tarmac has a long-term commitment to ensuring the long-term future of the monuments and we are delighted to donate this extremely important historic site to Historic England. With his help, Thornborough’s central and southern heritage will be protected and preserved for years to come.
“We hope that the public will enjoy this wonderful ancient site once it is accessible to them.”