In the age of Instagram, people have taken to building “cairns” – which is Gaelic for “heap of stones” along popular hiking paths as a way to tell the world (through a photo) that they’re been there and done something cute.

Experts say building them for that reason isn’t cool, though, and they have some advice on what you should do if you see them in the wild.

Rock cairns are typically build to show hikers which way to go on routes that can be confusing. Now, though, they’re showing up around particular features or rest stops, and there are sometimes many of them in one place.

They’re thought to have been started by Waldron Bates, the lead author of an island map published in Ireland in 1896. He wrote a handbook to establish standards and care for hiking trails, and suggested the way cairns – then known as Bates cairns – which were more than just simple stacks of stones.

But while their intended purpose of fostering community and assisting those who might otherwise lose their way, the US National Park Service says that building ones just for looks is potentially confusing.

Also, the first rule of interacting with the wilderness is to leave no trace.

Moving stones can disturb wildlife, contribute to soil erosion, or destroy habitats that plants and tiny critters need to continue to thrive.

Not to mention that with 297 million people hiking in national parks every year, if everyone left a cairn behind it could be a real problem.

The US Parks Department says that all of the unauthorized cairns are confusing walkers who think they can use them for navigation, warning that you should always trust a map or your GPS instead.

The Parks Service asks that if you see a cairn to leave it alone, and to not add any more along the trail, either.

In the immortal words of The Beatles: let it be.