Where do cairns come from?

As any hill-walker will know, the hills and mountains of the UK are dotted with piles of stones. These 'cairns' appear in all sizes, from a small cluster on an otherwise grassy plateau, to enormous constructions 10 metres across.

They appear on summits, on slopes and exposed shoulders, and in lines leading along routes. Some are marked on maps and some seem to appear overnight, only to vanish again in a few days time. What's striking about cairns is that there are a number of reasons for their creation, which span the history of man's impact on the uplands.

The oldest cairns on our hills were built in the early Bronze age, roughly 4000 years ago. They were burial mounds thought to be for important individuals, placed to be seen for miles around, and because mountains were seen as sacred.

Many cairns have been excavated and found to include artefacts and central chambers. The massive cairns sometimes found on summit areas, especially in the Carneddau of Snowdonia (carnedd means cairns), are good examples of burial sites, but smaller ones have also included remains.

In addition to this, there is a theory that when areas of land were cleared of stones to create fields, the stones were piled up to form cairns, but these are unlikely to be on mountain summits. And later on, before clan battles in Scotland, the army would build a cairn with each man adding a stone, with the survivors then removing a stone each to leave a monument for those that had not survived.

More recent cairns have been made by landowners and charities to direct people in mist or when snow covers paths. They appear at key junctions, or in rows over rocky terrain where the path is not distinct, such as on Ben Nevis and the Glyderau.

A problem arises when walkers enlarge and proliferate cairns, carrying a stone each to summit they visit and adding them to the cairn already in place. This practice has been discouraged by the Lake District National Park as it began to cause erosion when people took stones from paths, and because the large numbers changed the skyline.

Although the practice of walkers adding stones to cairns has died down, there is a running problem of people building cairns in all sorts of places, from random patches along paths, to summit plateaus.

Some are built to cover litter, some to act as memorials, and some simply to leave a mark on the mountain. All these reasons go against the 'leave no trace' philosophy, can lead to people making navigational errors, and have given rise to debates about what to do with them.

Organisations that take care of the mountains have a tricky job when it comes to cairns. They have to protect the genuine ancient sites, decide where to put navigational cairns, but also where to remove them. The John Muir Trust, who own most of Ben Nevis, have recently decided to destroy any new cairns that appear, and other bodies also send groups up the hills in their respective areas to pull them down and scatter the stones.

The message for walkers is simple, and is that we should leave no trace of our presence in the hills. Cairns are monuments and way-markers that appear all over the world, and apart from a few exceptions where they appear as art, they should remain as such.

Mimicking them to bury our refuse or taking stones to add to current ones changes the landscape. A good guided walk will always point this out, and rather then building a cairn of your own, take the time to marvel at these remnants of life from 2000BC which have withstood the harsh elements and are very much part of our mountain culture today.