The system covers roughly four kilometres from northwest to southeast and around two kilometres from southwest to northeast, running from the area of Poulbaun in the north down to Rannagh West in the south. What makes it quietly arresting is not any single feature but the sheer accumulated density of it: the walls meander rather than march, following contours and older logic rather than surveyor's lines.

Within and alongside the walls lie cashels, enclosures, hut sites, and wedge tombs. A cashel is a stone-walled ringfort, typically Early Medieval in origin, while a wedge tomb is a Neolithic or Early Bronze Age megalithic burial monument, its name describing the tapering shape of the stone chamber. The presence of both together suggests that this landscape was not organised in a single period but accumulated across thousands of years of human use, each generation adding walls, shelters, and boundaries to what already existed. The field system as a whole represents that kind of slow, layered occupation that upland terrain in the west of Ireland sometimes preserves, partly because the land was eventually abandoned and never ploughed into uniformity.