It measures roughly four metres north to south, just under three metres east to west, and rises to about ninety centimetres, with patches of heather-covered sod breaking through the upper surface. To most eyes passing through the hills of Garranes, it would look like little more than a casual accumulation of field clearance. It is, in fact, a cairn, a deliberately constructed stone mound of prehistoric origin, and its modest dimensions contain a long human prehistory.

Cairns of this kind are found across Ireland and the wider Atlantic fringe of Europe, and while their purposes varied, many served as burial monuments or territorial markers, their placement on elevated or sloping ground often suggesting an intention to be seen across a valley. What makes this example quietly interesting is its companionship: a second cairn sits approximately fourteen metres to the west, close enough that the two were almost certainly part of a related complex or series of monuments. Together they overlook the Glantrasna River valley, a position that would have carried significance for whatever community placed them there, whether as landmarks, graves, or ceremonial points in the local landscape.