Roughly twelve metres in diameter and circular in plan, it has subsided over centuries into the surrounding blanket bog, though a stretch of revetment, the stone facing built to hold the cairn's outer edge in place, remains visible on the northern side. Near the centre, a small raised mound betrays more recent intervention, where the structure has been partially rebuilt at some point.

Cairns of this kind are among the most enduring marks left on the Irish upland landscape. Built typically during the Neolithic or Bronze Age as burial monuments or territorial markers, they were constructed by piling stone, sometimes over a chamber containing human remains, and faced with carefully placed kerbing or revetment to give the mound a defined, deliberate form. The example on Stookeen is modest by the standards of great passage tombs, but its placement on a summit overlooking the Derrynasaggart range is consistent with a pattern seen across Ireland, where hilltop cairns seem as much concerned with visibility and presence in the landscape as with any single burial function. The Derrynasaggarts themselves straddle the Cork and Kerry border, a high, largely unimproved terrain that has preserved many such features simply by remaining outside the reach of agricultural improvement.