Piles of stones left by walkers as markers are being blamed for causing erosion on one of Wales’s most iconic peaks.
And there are fears the stones could endanger lives as they could be misleading.
The stones known commonly as cairns are used as trail markers on mountains to identify paths, junctions or dangerous places.
However, recently it has become customary for walkers to identify the routes they have taken by placing stones on a pile of stones, thereby creating a cairn.
On Cadair Idris the practice has become such a problem that the senior warden for South Snowdonia is organising a day of reducing the size and number of cairns with volunteers.
Simon Roberts, senior warden, said:
“As the cairns are built, stone by stone, the footpaths are eroding and the fragile landscape is being damaged.
“Footpaths widen and the cost of maintaining the footpaths increase.
“But, even more dangerous, they can mislead walkers, especially in fog.
“Later this year, we will begin to rationalize the cairns, but in the meantime we are appealing to walkers to stop moving the stones on the mountains.”
Warden Myfyr Tomos added:
“On the T? Nant footpath, within less than a mile between Rhiw Gwredydd and Bwlch y Cyfrwy, there are 102 cairns, and at the base of each cairn a very large hole where stones have been lifted from the path and adjacent land.
“Some of the stones are huge and the cairns are increasing every week.
“We need to ensure that future generations can enjoy walking the paths and mountains of Snowdonia. Reducing erosion by encouraging people not to move the stones is a way of contributing to this.”
Paul Williams, manager of the Cadair Idris Nature Reserve on behalf of Natural Resources Wales said:
“Building’ cairns has been of great concern over a number of years – the practice, by now, is totally unreasonable, creating scars on some of our most significant landscapes.
“The practice damages fragile habitats such as the moorland in the uplands and the scree, together with the animals and the plants associated with them.
“A cairn should only show the summit of a mountain where historical cairns are already there.”