Known locally as Lismore or An Lios Mór, it is a rath, the Irish term for a ringfort, a type of enclosed farmstead typically built during the early medieval period, between roughly the fifth and twelfth centuries. What makes this one quietly interesting is not just its size, nearly 62 metres across at its widest point, but the layered evidence of how it has been altered, encroached upon, and repurposed across the generations.

The enclosing bank, built from earth rather than stone, survives in varying condition. At its best-preserved points it rises to about 1.55 metres on its outer face, though it stands only around 0.8 metres on the interior side. A fosse, that is a ditch dug to accompany the bank and heighten the sense of enclosure, can still be faintly traced on either side of a substantial gap in the northern stretch, where around 23 metres of bank has been removed entirely. A field wall running along the southern edge has disturbed and partly demolished the bank there too, the ordinary logic of later agriculture indifferent to what lay underneath. The original entrance has not been identified with any certainty. Just west of the northern gap sits the outline of a small sub-rectangular hut, its enclosing bank of earth and stones no more than half a metre high, enclosing a modest area of roughly 2.5 by 3.2 metres. The interior of the larger enclosure, meanwhile, is covered in cultivation ridges running north-west to south-east, the faint corrugations of former lazy beds pressed into the ground and left there.