Cairns aren't great but please don't kick down every one you see while hiking. Doing so can be far more damaging than their building ever was, much less keeping them as is. From the NPS guidelines :
If you come across a cairn, do not disturb it. Don’t knock it down or add to it. Follow the guidelines from the Leave No Trace Center for Outdoor Ethics to ensure future hikers can navigate the trail and prevent damage to the landscape:
Do not tamper with cairns – If an intentional cairn is tampered with or an unauthorized one is built, then future visitors may become disoriented or even lost.
Galxybrain tip: Don't Fuck With Things. If you see a thing and don't know why it's there, what it is or how it works, DONT FUCK WITH IT. You aren't a toddler and should have that kind of self control.
Cairns aren't great but please don't kick down every one you see while hiking. Doing so can be far more damaging than their building ever was, much less keeping them as is. From the NPS guidelines :
Galxybrain tip: Don't Fuck With Things. If you see a thing and don't know why it's there, what it is or how it works, DONT FUCK WITH IT. You aren't a toddler and should have that kind of self control.