That alone would be unremarkable, but nobody is quite sure what they were for. The feature sits at the heart of a rath on a north-northeast-facing slope in hilly coastal pasture at Toberawnaun, and while much about the site fits the familiar pattern of early medieval enclosure, those perpendicular ridges, each roughly two metres long and just thirty centimetres high, resist easy explanation.

A rath is a ringfort enclosed by an earthen bank rather than stone walls, typically used in early medieval Ireland as a farmstead and marker of social status. This one follows the type closely enough: a roughly circular raised area some 21 metres across, bounded by a bank of earth and stone nearly six metres wide. The original entrance, facing east-southeast, was stone-lined and about 2.2 metres across, wide enough for livestock or a loaded cart. There is no fosse, the encircling ditch that often accompanies such sites, which is relatively unusual. A short distance inside the western field boundary sits a slightly raised house platform, the kind of levelled terrace on which a timber or wattle structure would once have stood. The western arc of the ringfort has not survived intact; the construction of a modern field boundary running roughly north-northwest to south-southeast cut through the perimeter and clipped the interior, erasing what was once a continuous earthwork. That kind of incremental loss to agricultural improvement is one of the more common fates of earthwork monuments across Ireland.

The two internal banks at the centre remain the site's most curious detail. They are modest in scale and show no obvious relationship to the entrance or the house platform. Their purpose, whether structural, ceremonial, or simply the remnant of some later subdivision of the interior, has not been established.