A rath, as these enclosures are sometimes called, is typically a roughly circular earthwork built during the early medieval period, most likely as a farmstead with a surrounding bank and ditch offering modest defence or social definition. The one at Knockforlagh sits just below a hilltop on an east-facing slope, and its position is the thing that makes it quietly difficult to categorise. The views from here extend in all directions, and that commanding situation has led to the conclusion that this was probably not a typical domestic ringfort at all.

The enclosure originally measured around 29 metres across at its widest, enclosed by a bank of earth and stone. Traces of a shallow external fosse, the ditch that would once have run around the outside of the bank, are still visible on the eastern side. The rest of the circuit tells a more melancholy story. The northern half of the monument has been levelled by land reclamation, and a post and wire fence now cuts across the northern interior on an east-west axis, marking the boundary between what survives and what does not. The bank remains visible only from the east through the south to the west. There is no clear original entrance; a gap in the southern bank appears to be a cattle gap cut in relatively recent times, two metres wide and obviously functional rather than ancient. The combination of an elevated, visually dominant location and the unusual scale of the enclosure sets it apart from the everyday enclosed farmsteads that dot the Irish countryside in their thousands, though without excavation, its original purpose remains uncertain.