It is neither. The structure, roughly eight metres across from north to south, is enclosed by a low dry stone wall about half a metre high and just under a metre thick, and on its eastern section stands a triangulation station, the kind of concrete or stone pillar erected by the Ordnance Survey to fix precise geographical coordinates across the landscape.

The giveaway to its origins lies in what is absent from the historical record. The enclosure does not appear on the first edition Ordnance Survey six-inch maps, which were produced for Ireland during the 1830s and 1840s, a period of remarkably thorough and systematic cartographic work. Its absence from that survey strongly suggests the structure was built later, most likely at the same time as the trig station itself, probably to demarcate and protect the survey point rather than to mark anything of earlier human significance. Triangulation stations were established across Ireland as part of ongoing geodetic work that extended well into the nineteenth and twentieth centuries, and a low enclosing wall of this kind would have been a practical way to define the survey point on exposed upland ground.

What the site does offer, quite apart from its utilitarian origins, is the wide and open view that made it useful in the first place. A mountain summit chosen for triangulation work needed clear sightlines across the surrounding countryside, and Glenaguile delivers exactly that.