When the Ordnance Survey teams passed through in 1839, local people told them the low mound, roughly 82 metres across and about 2.1 metres high, contained the graves of three kings of Ireland, and that this was the origin of the name Killaree, meaning the Cell of the Kings. Small heaps of stones and thorn bushes scattered across the interior were pointed to as evidence of stone buildings long since collapsed, giving the whole enclosure an air of something deliberately obscured.

The scholarly record complicates that romantic etymology. The historian Carrigan, writing in 1905, translated the townland name not as a royal cell but as Cill Láithrigh, meaning the Church of Laithreach, and traced the ancient place-name back to a document of 1247 in which it appears as "Lavertach". Carrigan noted plainly that the church itself had long since disappeared. The earthwork, then, is most likely the remnant of an ecclesiastical enclosure rather than a royal burial site; the surrounding bank, a roughly circular feature approximately four metres wide and standing up to 2.5 metres on its outer face, is the kind of boundary that would have defined an early medieval religious settlement. A causewayed entrance about four metres wide in the south-east quadrant appears to be original, and the raised, irregular features within the interior may represent the footprints of a church and associated buildings, though no clear plan has been recovered from them. The fosse, or surrounding trench, mentioned by the 1839 surveyors as still faintly visible on the south-east side, has since vanished, probably filled in at some point in the intervening years.