The original entrance has been lost entirely, the surrounding fosse, the defensive ditch that once ran around the outside of the bank, has silted up almost everywhere except along its southern arc, and quarrying on the eastern and south-eastern exterior has bitten into the monument's edges. What remains is a subcircular enclosure, roughly 41 metres across its longer axis, with an interior that rises gently from the perimeter toward the centre, a detail that hints at the deliberate shaping of the ground inside.

This is a rath, the Irish term for a ringfort, the most common type of early medieval settlement monument in Ireland. Raths were typically built between roughly the sixth and tenth centuries and served as enclosed farmsteads, their earthen banks and ditches marking out a household's space rather than defending against serious military threat. The Bryanmore example fits the general type well: a single bank, an external fosse, and a modest interior. Surveyors who recorded it in 1971 and again in 1976 noted that the fosse was best preserved along the south, while elsewhere the centuries had gradually filled it in. A modern field boundary now wraps around the monument from the south, west, and north-east, which has helped fix its outline in the landscape, even as the original form has softened and blurred.

The site sits on ground with open views to the north-west, north, and south-east, a position that would have made practical sense to whoever chose it. Early medieval farming families often selected slightly elevated spots, not for drama but for drainage, visibility, and a sense of boundary in an otherwise open countryside. The quarrying that has damaged the eastern exterior is a reminder of how routinely these monuments were treated as convenient sources of stone and rubble long before their age or significance was widely understood.