A team of archaeologists has unearthed a Neolithic "cathedral" - a massive building of a kind never before seen in Britain, which go back nearly 5,000 years, easily predating the Egyptian pyramids.
According to a report in The Press and Journal, the "cathedral", at 82 ft long and 65 ft wide, is placed between two of Orkney's most famous Neolithic landmarks, the Ring of Brodgar and the Stones of Stenness.
Even the Ring of Brodgar and the Stones of Stenness would have seemed quite small in the presence of the cathedral-type building, which would have stood on the spot that has now been excavated.
Nick Card, from the Orkney Research Centre for Archaeology, who is leading the dig, said the building was effectively a cathedral for the north of Scotland.
"It's spectacular," he said. "There were hints at the end of last season that we had an enormous building here and now we are able to define it more," he added.
What is interesting is that the shape and size of the building are visible, with the walls still standing to a height of more than three feet.
They are 16 feet thick and surround a cross-shaped inner sanctum where the excavation team have found examples of art and furniture created from stone.
It seems that the building was surrounded by a paved outer passage. This could have formed a labyrinth that would have led people through darkness to the chamber at the heart of the building.
"This is architecture on a monumental scale and the result is the largest structure of its kind anywhere in the north of Britain. It's one of those finds of a lifetime," Card said.
The building probably served as some kind of temple, maybe for remembering the dead. It may have been a place where sacrifices, even human sacrifices, were offered up.
Other buildings, over 50ft long and 30ft wide, have also been discovered.
According to Dr Colin Richards, a leading expert on the period, the building would have stood at the heart of Neolithic Orkney.
"A structure of this nature would have been renowned right across the north of Scotland - and is unprecedented anywhere in Britain," he said.