Heritage experts are investigating after graffiti was found carved into ancient standing stones which are legally protected.
Historic Environment Scotland (HES) staff found the markings on a visit to monitor the condition of the Machrie Moor standing stones on Arran.
The site is described as a “particularly well-preserved landscape of Neolithic and Bronze Age monuments”.
HES said that the stones are a scheduled monument, which means they are legally protected and damage to them, such as graffiti, is a criminal offence.
The organisation said it will be working with Police Scotland to investigate the incident.
In a post on social media, HES wrote: “On a recent visit to monitor its condition, we were concerned to discover that one of the stones has been damaged by incised (i.e. carved) graffiti.
“As well as being a Property in the Care of Ministers, the standing stones are also designated as a scheduled monument.
“This means they are legally protected and damage to them, such as graffiti, is a criminal offence.”
It added: “Heritage crime can cause damage that can never be repaired and forces us to spend less resources on important conservation work.”
The stones are thought to have been used for religious and ceremonial activities by the people that lived there.
The “rich archaeological landscape” includes standing stones, stone circles, burial cairns and cists, as well as hut circles and an extensive field system, which all date to between 3500 and 1500 BC.
