What makes it worth a second look is not its size, which is modest, but its combination of features: a subcircular enclosure, a rock-cut ditch, an unfinished outer bank, and, tucked into the interior, a souterrain. A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval settlement in Ireland, and their presence within a ringfort usually signals that the site was used as a dwelling place rather than purely a defensive one.

The enclosure measures roughly 17.7 metres east to west and 15.4 metres north to south, defined by an earthen bank some five to six metres wide. The bank drops only slightly on its inner face, between 0.2 and 0.8 metres, but rises considerably more steeply on the outside, reaching between 1.5 and 3 metres above the surrounding ground. Beyond that bank runs an outer fosse, a ditch, which is partly cut directly into the bedrock on the eastern side. An additional external bank runs from the south-east around to the west, but it is not completed on all sides, which gives the site an unfinished or perhaps pragmatic quality, as though the builders judged certain approaches already sufficiently protected by the terrain. A two-metre-wide entrance breaks through the inner bank on the north-east side, and the souterrain lies just inside, in that same north-eastern portion of the interior. A mountain stream runs roughly 70 metres to the north-west, which would have made the location practical for anyone living within the enclosure. The site is recorded under the name Lissinagroagh, written in gothic lettering on the 1910 edition of the Ordnance Survey six-inch map, and it sits on a slight east-west ridge that gives the interior a gentle southward aspect. Michael J. Moore included it in the Archaeological Inventory of County Leitrim, published in 2003, which remains the principal systematic record of such sites across the county.