The arrowhead may have been lost from a private collection
Archaeologists have made what they described as a "chance discovery" of a stone arrowhead in the garden of a ruined schoolhouse in Sutherland.
Glasgow University Archaeological Research Division (Guard) said it may have been dropped by a hunter.
It added that it may have arrived from elsewhere and then been lost by a local collector or a teacher at the former parish school in Durness.
The 3cm relic was made from a sedimentary rock called black chert.
In a report by Guard made available on Highland Council's Highland Historic Environment Record, archaeologists said the find had "cast an unexpected light" on the area's prehistoric times.
The spot on rocky ground between two lochs was a perfect place to stalk game, they said.
But the archaeologists added that it could have been lost from a private collection after being found somewhere else locally.
Guard's investigations at the schoolhouse at Loch Croispol is part of community company Durness Development Group's wider efforts to interpret the area's past.
Durness Parish School in the far north fell into a ruined state after its last master was sacked in 1861.
Built in the 1760s, following a campaign by local minister the Reverend Murdo MacDonald, the school had a classroom and accommodation for its teacher.