QUARRY firm Tarmac is offering to give to the nation 60 acres of land around the controversial Thornborough Henges site in North Yorkshire.

The surprise move could mean some of the ancient earthworks would be visible for the first time in living memory.

Tarmac says the Neolithic henges - subject of an intense preservation campaign - are attracting more and more visitors.

"We think the time is right for this land to be donated to an appropriate conservation body," said Tarmac area director Simon Phillips.

The offer comes just days ahead of a county council site visit connected with plans to extend quarrying near the monument.

Two protest petitions with thousands of signatures have been lodged with the council, which only last week decided to hold a special meeting to consider the Tarmac scheme.

Campaigners claim quarrying would disturb important archaeological remains.

Most of the land involved is next to the northernmost henge - the best preserved of the three monuments near Bedale. The site is being offered as a gift, together with the 1.5m tonnes of sand and gravel reserves beneath the surface.

Tarmac has also agreed to work with the owner of neighbouring land and with English Heritage to discuss removing trees and vegetation which mask the northernmost henge.

It is this move which would unveil the henges and enable archaeologists to make the first comprehensive survey of the complete complex.

Mr Phillips said: "We will give the land to English Heritage or a suitable charitable trust. In the past, English Heritage has declined the chance to take over responsibility. We hope it will agree to this new proposal.

"The gift will enable the area to be put down in perpetuity to pasture.

"For the first time ever, the setting of the northern henge will be preserved as an archaeological reserve."

Mr Phillips said he looked forward to working with English Heritage and North Yorkshire County Council to develop the charitable trust.

The donation would include Tarmac making available its visitor centre and car park at the entrance to Nosterfield quarry, about half a mile from the monument, for the use of sightseers. There would also be a footpath for visitors to get to the reserve.

Mr Phillips said this was a major step towards conservation of the monument.

The area concerned is equal to 60pc of the quarrying site proposed in the planning application to extract sand and gravel from Ladybridge Farm.

Responding to archaeological concerns, a 7-acre section of the Ladybridge site would also remain undisturbed.

The county council has fixed September 20 as the date for the special meeting and Thursday for the site visit.