Hikers in France warned against building ‘cairns’ on trails and paths

Hikers in France are being warned against building ‘cairns’ – small piles of pebbles or stones – along trails or paths, as experts warn the practice can cause real damage to fragile ecosystems.

Building cairns as a way to mark your hiking route has become more popular in recent years, especially on social media. On Instagram, there are now 2.3 million posts under the hashtags #cairns and #rockbalancing, and 160,000 under the hashtag #rockstacking.

The word ‘cairn’ comes from the Celtic word ‘karn’, which means ‘pile of stones’. Cairns are found all over the world, near water, glaciers, and in the desert. In some Nordic countries they were even found in the middle of water, as a means to help navigation.

And yet, their growing popularity – especially of ‘giant’ piles – has prompted managers at the Parc national des Calanques (Bouches-du-Rhône) to warn that building them in such large numbers puts ecosystems at risk. More information can be found on the national park website here.

This is because the stones used would otherwise protect the soil and land from erosion. Moving them can cause soil to shift and change more than it would if left undisturbed.

Similarly, in the Calanques, a small white flower, the sabline de Provence (which is a protected plant) only grows in the limestone between Toulon and Marseille, and disturbing the balance of the land ecosystem puts it at risk.

Insects such as the yellow-tailed European scorpion, and two species of gecko, also live in the stones. Moving them can disturb these animals.

Lastly, if hiking paths become overrun with cairns, this can lead hikers to walk next to the trail, trampling over other shrubs that the path was initially intended to bypass.

The Calanques park is not the only natural space to issue a warning about the cairns. Environmental associations in Brittany, and even in Tenerife in the Canary Islands have made similar statements.

At the Pointe du Van on Brittany’s Crozon peninsula, where the situation became particularly bad in 2016, the community set up dedicated spaces so that families can build little cairns using a pre-selected, limited stock of stones. This has significantly helped the wider issue.

In protected areas, people can be fined up to €135 for moving stones, and on beaches, removing sand, pebbles or shells can be fined as much as €1,500. The Environmental Code states that this is especially true if there is a “risk of compromising the integrity of beaches, dunes, cliffs…[and] marshes”.

In contrast, the rules do not apply to driftwood or seaweed. These are considered ‘laisse de mer’ (tidewrack) - the remnants of the sea brought in by the tide.

The Calanques de Marseille has recommended that rather than contributing to the #cairns or #rockstacking hashtags, social media users should instead promote #stopcairn and the #leavenotrace movement.

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