Ever go on a hike and see piles of deliberately stacked rocks? You're not alone.
A cairn is a man-made stack of stones that have a wide variety of historical usage, dating back to early pre-history. In modern times, cairns have been used as landmarks and trail markers. Historically they have been used as burial monuments
In the Americas, indigenous persons have used cairns as trail markers, directional navigators and herding tools.
On the trail, placing cairns can help guide hikers to avoid dangerous paths or to signify that they are going off trail. At summits and peaks, cairns are often organized to signify the accomplishment of reaching the peak. Wherever and however you organize your cairns on the trail, make sure the next hiker will be helped by the markings.