It is an incongruous fate for a fosse, the term for the external ditch dug to reinforce a ringfort's bank, and it says something about the ambiguous status these monuments occupy in the Irish countryside: old enough to be vaguely respected, not prominent enough to be protected from the practical needs of a working farm.

The ringfort itself, a rath, is a roughly circular enclosure measuring approximately 29 metres across on its north-to-south axis. Raths are among the most common archaeological monuments in Ireland, typically constructed during the early medieval period as enclosed farmsteads, the earthen bank and fosse serving as much for status and the corralling of livestock as for defence. At Derraulin, the bank still stands to a considerable 3.3 metres on its exterior face, though only about half a metre remains visible on the interior, suggesting a good deal of material has slumped or settled over the centuries. Field boundaries have grown up against the northern and north-western edges of the enclosure, folding it into the agricultural landscape that has long since replaced whatever settlement it once sheltered. The site details were compiled by Denis Power and recorded on the national monuments database, with the upload noted in August 2011. Roughly 20 metres to the north-east lies a separate moated site, a later medieval feature typically consisting of a platform or island surrounded by a water-filled ditch, indicating that this small patch of Limerick pasture was in active use across several distinct periods.

The enclosure sits atop a low rise in what is now pastureland, though accessing or inspecting the interior is unlikely to be straightforward. The bank and the ground within are described as heavily overgrown with briars, bushes, and nettles, the kind of vegetation that accumulates precisely because the land inside is left undisturbed. Anyone visiting should expect the exterior profile to be more legible than anything within. The fosse to the south, now used as a dump for old cars, is visible evidence of the monument's current condition rather than its former character. The proximity of the moated site to the north-east is worth bearing in mind; two monuments this close together, from different periods, suggest a landscape that rewarded repeated settlement even if nothing above ground now makes that obvious.