Walkers asked to stop moving Snowdonia National Park stones
Walkers have been urged not to move stones and build stacks of rocks in Snowdonia over fears it is damaging the landscape.
Snowdonia National Park has issued the appeal in a bid to stop people creating cairns - piles of stones.
It said the practice has "become customary" among walkers so they can "identify paths and junctions or dangerous places".
But park wardens warned it has caused footpaths to erode.
On Ty Nant footpath, within less than a mile between Rhiw Gwredydd and Bwlch y Cyfrwy, there are 102 cairns.
Simon Roberts, senior warden for south Snowdonia, said the issue has become "quite a problem" on Cadair Idris, leading to a volunteer day being organised to reduce the size and number of piled stones.
"As the cairns are built, stone by stone, the footpaths are eroding and the fragile landscape is being damaged," he said.
"Footpaths widen and the cost of maintaining the footpaths increase. But, even more dangerous, they can mislead walkers, especially in fog."