It is one of the best preserved Stone Age villages in Europe, but Skara Brae in Orkney is just a few metres from the sea and it is a constant battle to save it from coastal erosion.
Experts warn as many as 10,000 historic sites around Scotland are at risk of being swept away, many of them unexcavated and unprotected.
BBC News Scotland Correspondent Lorna Gordon has been to visit the Neolithic community to see what measures are being taken to protect it.
It is a Stone Age village of subterranean houses abandoned 5,000 years ago - now tourists travel from all over the world to Skara Brae to get a 3D glimpse of what Neolithic life might have been like.
They see remarkably well preserved and well ordered homes, each with a dresser, beds, a hearth, and underground passageways linking one house to another. All that's missing are the roofs.
We don't know exactly how much has disappeared into the sea over the years before proper coastal defences were put in
Julie Gibson Orkney archaeologist
What remains is made of stone and that's part of the reason Skara Brae has survived so long. The other is that when the village emptied of people it was slowly covered over by grass and sand.
For thousands of years it was hidden from view and protected from the harsh island weather, and it is that weather whipping up the sea nearby which is still Skara Brae's greatest threat.
Orkney archaeologist Julie Gibson says recent geophysics have uncovered more of the village a short distance inland, but adds: "We don't know exactly how much has disappeared into the sea over the years before proper coastal defences were put in."
Those defences are well maintained by Historic Scotland and added to every year. But on a walk around the 4m-high coastal wall, Stephen Watt from Historic Scotland explains some of the challenges they face.
Pointing to one part of the wall he admits that a storm three years ago brought trouble.
He said: "This particular bit was badly damaged. There was a hole you could almost walk into. It drew out a huge amount of material from behind the sea wall."
Last year another part of the wall was rebuilt down to the bedrock to stop water getting underneath.
Inside Orkney's Stone Age village
Stephen Watt says they have discovered that the greatest erosion is occurring where the hard stone of the sea wall meets the sand. If that continues he says it is possible that the sand might erode back and that the sea would come round the side of Skara Brae.
So now Historic Scotland, along with other organisations, is monitoring the entire bay to work out the rate of erosion and where it is worst. Future repairs will be based on the results of this wider study.
Skara Brae will always be protected, but take a walk a little further down the beach and there's a good illustration of the threat to other unprotected and unexcavated historic sites.
In the dunes just a few hundred metres away there's a line of stones jutting out from a wall of sand. Tom Dawson from the Scape Trust, a charity researching Scotland's coastal archaeology, says pieces of pottery and other artefacts indicate they are the remains of an Iron Age wall, possibly as much as 2000 years old.
He draws a comparison between the two sites, saying: "Without a coastal defence Skara Brae would be washed away in exactly the same way that this site is being washed away. At the moment this site looks quite stable, but a single storm could come in, undermine the sand and all the stone here would come collapsing down."
Scotland has thousands of historic sites around its coastline. Archaeologists would like to document as many as possible before coastal erosion washes some away, but some are already disappearing.
Julie Gibson tells me of a site on Westray which is 2000 years old and where until a few years ago "you could see the front doors coming out onto the shore, you could crawl into rooms from the beach," now she says those rooms are half gone.
The Scape Trust has already helped organise community digs in several parts of Scotland.
They would like to do more, gain as much knowledge about how people used to live from other archaeological remains before some of them are lost to the waves forever.
But with so many sites unexcavated and potentially under threat Tom Dawson admits that in this race against time it would be unrealistic to save them all.
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