Another one; "Cambria Archaeology has recently been working with the Brecon Beacons National Park and Cadw on a project to record and protect the remains of a Bronze Age burial mound at Fan Foel on Mynydd Du, Carmarthenshire (SN 8215 2234). The condition of the monument was recorded in June 2002 as part of the Cadw-funded Prehistoric Funerary and Ritual Sites Assessment project. It was observed that the barrow had been suffering from severe erosion both from the wind and rain and from visitors moving stones to form a 'walker's cairn'. "

It seems to be a growing problem, people apparently also make "walker cairns" so that in the end you can't distinguish real cairns from the walker cairns that mark out their achievments when they reach a particular summit or ridgeway. So perhaps its a good

but rather sad happening that cairns have to be covered..

Expect everyone has an opinion one way or the other :)