Walkers at Ben Nevis and other mountains in Scotland have been warned not to build mini rock piles because people are hiding their poo in them.

The piles of rock - known as cairns - are a feature of mountain walks, with many official examples along trails, but a number of DIY cairns are being constructed to hide rubbish and even human excrement.

Fran Lockhart, from conversation charity the John Muir Trust, told The Guardian: “When we take some of these cairns to bits we find things underneath, like rubbish and even piles of poo.

“Occasionally you get one which is quite robust and built as a memorial.

“It just gets bonkers – it takes one or two people to start it and now it’s gone daft.”

The official cairns are used as markers to guide walkers, particularly if it is snowing in winter.

The makeshift cairns are being removed from the summit of Ben Nevis.

“People think it’s a fun thing to do but we would prefer them to leave the countryside as it is,” said Mr Lockhart.

“They detract from the scenery and now we clear any new cairns that appear on the summit.”

(Picture: Rex Features)