What makes this particular rath slightly curious is a detail lodged in an Ordnance Survey Name Book from the 1840s: surveyors who were busy mapping Ireland in that decade planted a trigonometrical station inside it, using the ancient enclosure as a convenient elevated point from which to measure the landscape. The fort, which they noted under the name "Ballynamaanagh Fort", was already old enough to be treated as fixed furniture.

A rath is an early medieval farmstead enclosure, typically dating from roughly the sixth to the tenth century, defined by one or more earthen banks and ditches and serving as a defended homestead for a farming family and their animals. This one measures approximately 28 metres north to south and 26.5 metres east to west, defined partly by an earth and stone bank and partly by a natural-looking scarp, a steep slope cut or shaped to serve the same defensive purpose. The bank itself is 4.6 metres wide, rising just half a metre above the interior but nearly 1.65 metres on the outside face, while the scarp on the southern and eastern arc reaches 2.2 metres. Slight traces of an outer fosse, a defensive ditch roughly 3.3 metres wide, survive on the east-south-east side. The interior was deliberately raised on the western side to level out the natural hillslope, and the ground then falls gently eastward toward a narrow entrance, two metres wide, with possible stone-facing still visible on the northern side of the gap. A separate earth and stone ridge, seven metres long and running on a north-west to south-east axis, sits in the north-east quadrant of the interior, its original purpose unclear. Boulders and stones have been piled against the eastern scarp over the years, and a cattle gap at the south-east indicates the site has been folded into ordinary farm use for a long time. About 14 metres to the south-east, an oval depression in the ground, shallow but distinct, kinks inward along its eastern and western edges in a way that suggests it is not simply a result of settling soil.