The circular monument lay hidden for centuries under farmland, its existence only hinted at in crop marks, spotted in aerial surveys.
But over the past three months archeologists have been hard at work bringing to light what they believe could be East Yorkshire’s first Woodhenge - as in Stonehenge without the stone - at Little Catwick Quarry near Hornsea. And it could have been used for ritual cremation - or even a sauna.
Built at least 4,000 years ago in the late Neolithic to Bronze Age, it was constructed out of a series of wooden posts.
Later an encircling ditch and bank was added with two opposing entrances, one facing north west, the other south east.
Intriguingly a pit was discovered in the middle of the henge containing heavily burnt stones, while others were found discarded in the entrances.
Lead archaeologist John Tibbles said the discovery of the Woodhenge was “exceptionally rare” - so rare they were asked to handsieve the contents of the surrounding ditches totalling 95 tonnes.
He added: “Normally when you mention ritual, archeologists laugh.
“But in this case it was ritual, it was a meeting place, where all the little groups could come together. We found a lot of burnt stones, but they weren’t burned in situ and therefore we think you could have ritual cremation there.
“It is possible that bodies were brought there to be cremated and then the remains buried elsewhere.
“There could be links with Sandsfield, a mile away, where there was a cemetery with a ring ditch with 37 urns, dating to the late Neolithic early Bronze Age.”
However discoveries at Marden Henge in Wiltshire have been throwing a new light on the way henges may have been used in Neolithic Britain and another possibility could be that at some time it was used as a sauna.
Finds there suggest people were heating up stones on an external fire then carrying them into a building and placing them on an internal hearth. People then sat around it on a ledge, pouring water onto the stones to bask in the steam in the same way native American Indians used sweat lodges.
It sounds unlikely but there have been similar finds, including a Bronze Age sauna on Orkney. Mr Tibbles said: “I’d like to totally dismiss it - but they have had them in Finland for 2000 years and there is Marden Henge.”
In the Spring the henge will be dug up as the quarry is extended.
However Mr Tibbles said the site had been painstakingly and methodically recorded under the supervision of the county archeologist.
Only one other henge has been discovered in East Yorkshire. Two years ago the Neolithic site, at Northorpe, near Hornsea, which was only recently identified in an aerial survey, was given special protection by Historic England.
A circular space with a ditch and a bank on the outside, it has been flattened by years of ploughing and was only visible as dark crop marks from the air.
Little Catwick is the largest privately-owned sand and gravel quarry in Yorkshire.
Apart from aggregates, it has yielded some amazing finds, including a mammoth tusk and a 4000 to 5,000-year-old highly-polished Cumbrian greenstone axe.
Mr Tibbles has been working at the quarry for seven years and says the site is “absolutely heaving” with prehistoric to late Roman finds.
Managing director John Bird said the henge “is a really interesting find and is something worth recording - it’s our heritage.”