An investigation has been launched into concerns that increased visitor numbers may be damaging the Stone Age village of Skara Brae on Orkney.
The village gives a snapshot of Stone Age life
The heritage agency, Historic Scotland, has brought in state-of-the-art technology to determine whether stones are moving or developing cracks.
The 5,000 year old site, which lies on the southern shore of Sandwick's Bay o' Skaill, is one of the most popular tourist attractions on the island.
More than 50,000 visitors explore the village every year and curators are seeking to strike a balance between access and conservation.
Skara Brae consists of 10 houses connected by a maze of passages, with some of the walls up to nine feet high.
Various pieces of stone furniture such as cupboards, beds and dressers have all survived.
The village, built before the Pyramids and the Great Wall of China, overlooks the Atlantic Ocean and is exposed to high winds and sea salt.
Steve Watt, a district architect with Historic Scotland, said wear and tear was taking its toll.
"We're concerned with the cracks in the stones and we're concerned with deterioration with some of the delicate carvings," said Mr Watt.
"Our studies will also look into the effects of the numbers of visitors at Skara Brae."
No 'immediate danger'
Scientific equipment has been brought in to see if the stones are moving and cracking and lasers are being used to see if inscriptions are being eroded.
The survey is expected to take a year but Historic Scotland said there was no immediate danger of collapse.
Curator Anne Marwick said there was an important balance to be struck between protecting the site and allowing visitors to experience what life was like 5,000 years ago.
"If the survey shows that visitors are causing problems within the site then Historic Scotland will take action to minimise any damage that is being done," she said.
"At the moment we're quite lucky because we have a certain amount of freedom - you can actually see the houses and get quite close to them and it would be nice to have that continuing if possible."