It is the kind of structure that could easily be walked past without a second glance, yet its geometry is deliberate and its construction, however ruinous, was clearly intentional. The perimeter is formed by a collapsed drystone wall, a technique requiring no mortar, built instead by carefully selecting and stacking stones so that their weight and interlocking shapes hold them in place. What remains stands roughly 0.75 metres high and measures 0.6 metres thick, with the northern side running straight for about 4.9 metres and the eastern side extending some 6.3 metres. The south-western side curves outward, giving the whole enclosure its irregular, roughly triangular form.

The eastern wall has a gap at its centre, which is likely the original entrance point. Just north of this opening, a short section of wall runs east to west for approximately two metres, forming a kind of internal stub or return. Loose stones are scattered around the outside of the perimeter, the gradual collapse of centuries slowly returning the structure to the hillside. Enclosures of this general type are found across Kerry and the wider Irish uplands, and their purposes varied considerably, from livestock management to more ceremonial or boundary-marking functions, though without excavation it is rarely possible to say with certainty what any individual example was built for or when. At Knocknagowan, the sloped, rock-broken ground and the modest scale suggest something practical rather than monumental, a modest human imposition on a landscape that has since largely reclaimed it.