The name, as the antiquarian T. J. Westropp noted in 1909, translates from Irish as something close to "the fort of the pillar-stone", yet the stone in question had already vanished by the time he recorded this. The name preserves a memory the landscape itself has lost.

The structure is a bivallate raised rath, meaning it is encircled by two concentric earthen banks with a fosse, or ditch, running between them. It sits on a flat terrace with a ridge rising to the north and ground falling away to the south, giving the whole site an open, slightly exposed quality. The inner enclosure measures roughly 28 metres in diameter, while the overall footprint extends to around 75 metres across. The earthworks have suffered over time; cattle have worn down parts of both banks and exposed the stone beneath, and the outer bank is considerably reduced along its northern arc. A gap on the west-northwest side, about 3.2 metres wide and accompanied by a slight causeway, is thought to be the original entrance. Beneath the interior, in the south-western sector, there is a souterrain, an underground stone-lined passage typically associated with early medieval settlement and used for storage or concealment. The fort was recorded by the scholar Eugene O'Curry in 1835 under the name "Lios an Chairn" and was known locally as Studdert's Fort by the mid-nineteenth century, the latter name reflecting the kind of informal attribution to local landowners that often obscured older identities. A separate standing stone survives in the adjacent field roughly 100 metres to the northeast, a reminder that the wider landscape here was once more densely marked than it appears today.