What makes the site at Lisroe, near Moneymore in County Galway, worth pausing over is its concentric arrangement: two separate rings of bank and fosse, one inside the other, with a flat berm roughly ten metres wide running between them. That doubled boundary, enclosing a space roughly 43 metres across, suggests something more deliberate than an ordinary agricultural settlement, whether a higher-status household, a site requiring unusual defence, or something whose purpose has simply dissolved into the ground.

The site sits on a rise in gently rolling pastureland, and despite centuries of agricultural activity it has survived in remarkably good condition. A stone-lined causewayed entrance gap, about six metres wide, pierces the southern side, and the outer bank remains traceable all the way around. The outer fosse, the rock-cut or earthen ditch outside that bank, is more fragmentary, surviving only from the south, around through the west, to the north-west. Field boundaries have cut through the outer bank at two points, and the inner bank and fosse have been quarried away at the north-east and east-south-east. Inside, the ground holds further detail: foundations of three possible house sites are visible in the eastern sector and south-western quadrant, and a grassed-over bank in the north-eastern quadrant suggests the interior was itself subdivided at some point. Perhaps most intriguing is the presence of a souterrain, an underground stone-lined passage of the kind commonly associated with early medieval ringforts, used variously for storage, refuge, or ventilation of byres. The antiquarian T. J. Westropp recorded all of these internal features in 1919, and a reference by Athy in 1914 documents the souterrain separately, placing the site's known scholarly history well over a century back.