At Gortnascreeny in County Cork, it is one of several features that give this otherwise quietly ordinary-looking earthwork an added layer of curiosity. The fort sits on level ground, but the ground drops away steeply to the south, giving the enclosure a commanding position over the slope below, even if that drama is not immediately obvious from within the pasture field where it stands.

A rath, as this class of monument is sometimes called, is a roughly circular enclosure defined by one or more earthen banks, typically built during the early medieval period in Ireland, broadly from around the fifth to the twelfth century, and used as a defended farmstead. At Gortnascreeny, the enclosure measures thirty metres across in both directions, making it a respectable example of the type. The earthen bank still stands two metres high on the interior face and is stone-faced in places, including around the causewayed entrance to the south-east, where the gap through the bank measures four metres wide. Outside the bank runs a fosse, a defensive ditch, cut to a depth of one and a half metres, with a counterscarp bank, a secondary raised lip on the outer edge of the ditch, adding a further barrier. The fosse remains waterlogged on its southern side. Inside, faint cultivation ridges run across the interior on a north-south axis, suggesting the enclosed space was put to agricultural use at some point after the fort's original occupation. Immediately to the east, in the adjoining field, lies a separate linear earthwork, and local tradition holds that the two sites were once connected by an underground passage, a souterrain perhaps, though no such feature has been confirmed in the recorded description.