The depression, measuring 1.7 metres in length and 1.3 metres in width, runs on a north-west to south-east axis, and it takes a trained eye to read it for what it is: the collapsed roof of a souterrain, an underground stone-lined tunnel or chamber built, typically in the early medieval period, for use as a refuge, a cool store for food, or both.

The souterrain sits within the north-west quadrant of a rath, the circular earthwork enclosure that formed the basic unit of rural settlement across early medieval Ireland. Raths, sometimes called ring forts, were typically the farmsteads of free farming families, their banks and ditches marking off a domestic space from the surrounding landscape. Souterrains were a fairly common feature within such enclosures, though many have gone unrecorded or been disturbed beyond recognition. At this example, some stone remains visible near the north-west end, along with what appears to be an entrance point. A slight rise in the ground beyond that end suggests the passage may have continued further to the north-west than the visible depression indicates, the line of it still faintly legible beneath the surface.