For the past several years, largely thanks to Instagram culture, rock cairns—those carefully balanced towers of rocks that look like something straight out of a Zen garden—have become ubiquitous across the natural landscape. It’s not terribly surprising, really. There’s something satisfyingly primitive about balancing rocks on top of one another, and the urge to create art and order out of the wildness of nature is a decidedly human instinct. Plus, they just look cool.

But according to environmental experts, that’s not a good enough reason to make them.

Rock cairns have become a wilderness battleground of sorts, with people loving to make them but many places making it illegal to erect them in natural areas. Even the freedom-loving state of Texas, where you can basically build a tower of guns as high as you want, has made building rock towers illegal in its state parks.

Why? As it turns out, stacking rocks isn’t as harmless as it may seem.

While no one is really worried about hurting rocks themselves, non-living as they are, there are entire ecosystems living under rocks that get disturbed when people build cairns. Rocks around waterways are particularly important for wildlife, as insects, fish, crustaeans and other animals lay eggs or make their homes under them. Even the algae that forms under and around rocks is an important part of river ecosystems, and when people pick up rocks to pile into a cairn, all of that gets disturbed or destroyed.

What about if you’re stacking rocks nowhere near a river? Well, in mountainous areas, rocks also help prevent erosion. An increase in erosion can increase pollution, decrease soil fertility and lead to more runoff, which can impact waterways and ecosystems down the line.

You may be thinking, “Yeah, but there are millions of rocks. Surely moving a few to make a cool, meditative rock cairn isn’t going to destroy the environment.” What it really boils down to is the “leave no trace” idea of protecting our natural areas. One person’s actions might have a minimal impact in the grand scheme of things, but what if everyone did it? Additionally, moving rocks from the wrong place can lead to rock and mudslides, which directly endangers humans as well.

The other problem with building rock cairns in random places is that real, official ones in specific places serve an important purpose. When built by authorities like park rangers, they are used to delineate a hiking path. Cairns, when purposefully placed by people who know the whys and hows and wheres of creating them, keep hikers safe by orienting them to official trails.

That’s one reason why, despite the righteous urge to do so, people shouldn’t topple cairns built by others, either. Yosemite National Park recently shared a video of a ranger knocking over a huge cairn and seemingly encouraged people to do the same, but in some places, cairns have been placed purposefully by park rangers. A cairn in the middle of a river? Not likely a trail marker. But out in the woods? Probably best to leave the toppling of those ones to the experts.

It may seem like people who rail against cairn-making are just grumpy buzzkills making a mountain out of a molehill—or a rock pile, in this case. But protecting the environment involves all of us taking actions both large and small. As the saying goes, when we know better, we do better, and experts have been asking people to refrain from moving rocks out of their natural places to protect the natural environment.

If you want to build a cairn in your own yard with landscaping rocks, go ahead and balance those stacks to your heart’s content. But out in the wilderness and in protected park lands, leave the rocks where they are, knowing that you’re helping keep the Earth itself in balance for all of her creatures.

For the past several years, largely thanks to Instagram culture, rock cairns—those carefully balanced towers of rocks that look like something straight out of a Zen garden—have become ubiquitous across the natural landscape. It’s not terribly surprising, really. There’s something satisfyingly primitive about balancing rocks on top of one another, and the urge to create art and order out of the wildness of nature is a decidedly human instinct. Plus, they just look cool.

But according to environmental experts, that’s not a good enough reason to make them.

Rock cairns have become a wilderness battleground of sorts, with people loving to make them but many places making it illegal to erect them in natural areas. Even the freedom-loving state of Texas, where you can basically build a tower of guns as high as you want, has made building rock towers illegal in its state parks.

Why? As it turns out, stacking rocks isn’t as harmless as it may seem.

While no one is really worried about hurting rocks themselves, non-living as they are, there are entire ecosystems living under rocks that get disturbed when people build cairns. Rocks around waterways are particularly important for wildlife, as insects, fish, crustaeans and other animals lay eggs or make their homes under them. Even the algae that forms under and around rocks is an important part of river ecosystems, and when people pick up rocks to pile into a cairn, all of that gets disturbed or destroyed.

What about if you’re stacking rocks nowhere near a river? Well, in mountainous areas, rocks also help prevent erosion. An increase in erosion can increase pollution, decrease soil fertility and lead to more runoff, which can impact waterways and ecosystems down the line.

You may be thinking, “Yeah, but there are millions of rocks. Surely moving a few to make a cool, meditative rock cairn isn’t going to destroy the environment.” What it really boils down to is the “leave no trace” idea of protecting our natural areas. One person’s actions might have a minimal impact in the grand scheme of things, but what if everyone did it? Additionally, moving rocks from the wrong place can lead to rock and mudslides, which directly endangers humans as well.

The other problem with building rock cairns in random places is that real, official ones in specific places serve an important purpose. When built by authorities like park rangers, they are used to delineate a hiking path. Cairns, when purposefully placed by people who know the whys and hows and wheres of creating them, keep hikers safe by orienting them to official trails.

That’s one reason why, despite the righteous urge to do so, people shouldn’t topple cairns built by others, either. Yosemite National Park recently shared a video of a ranger knocking over a huge cairn and seemingly encouraged people to do the same, but in some places, cairns have been placed purposefully by park rangers. A cairn in the middle of a river? Not likely a trail marker. But out in the woods? Probably best to leave the toppling of those ones to the experts.

It may seem like people who rail against cairn-making are just grumpy buzzkills making a mountain out of a molehill—or a rock pile, in this case. But protecting the environment involves all of us taking actions both large and small. As the saying goes, when we know better, we do better, and experts have been asking people to refrain from moving rocks out of their natural places to protect the natural environment.

If you want to build a cairn in your own yard with landscaping rocks, go ahead and balance those stacks to your heart’s content. But out in the wilderness and in protected park lands, leave the rocks where they are, knowing that you’re helping keep the Earth itself in balance for all of her creatures.