What is believed to be evidence of a lightning strike has been found on a remote Highlands mountain.
Channels have been found gouged into the ground and washing machine-sized boulders dislodged near the top of 909m (2,982ft) Leum Uilleim.
Allan Macleod, head stalker at Corrour Estate, said at first glance it looked like the damage was caused by a large mechanical digger.
But he said this was impossible given the location.
The nearest place people can reach the mountain is more than a mile away at Corrour Station, one of the UK's most remote and highest railway stations. There is track, but not a public road to the station.
Leum Uilleim, which overlooks sprawling Rannoch Moor, is a Corbett, which are Scottish mountains of between 762m (2,500ft) and 914m (3,000ft).
Mr Macleod said he believed the only plausible explanation for the damage was a lightning strike.
He said there appeared to be a point of impact near the mountain's summit. The channels began less than a metre away and may have followed small water courses on the hillside.
Mr Macleod said: "The boulders were two or three feet square in size and the channels in the ground were up to 40ft long.
"Also, any diggers working on Corrour I would have known about, especially in such a remote location."