This is a souterrain, an underground passage or chamber built from stone, typically constructed during the early medieval period as a place of storage or refuge. What makes this one immediately striking is its scale: the pit stretches to over nineteen metres in length, though its base narrows to little more than a metre wide, giving it the character of a deep, deliberate channel cut into the earth rather than a broad excavation.

The souterrain sits within the south-western quadrant of a rath, a type of circular earthwork enclosure that was the most common form of rural settlement in early medieval Ireland. That enclosing rath holds the status of a National Monument. The souterrain itself survives in a partially collapsed state, now visible as an open hollow up to 4.3 metres wide at its broadest point and around 0.8 metres deep. Along the southern end of this hollow, three capstones remain, each placed transversely across the trench as a roof would have been. Two of these, measuring roughly 0.55 metres wide and 0.23 metres thick, are still in their original positions. The third, at the southernmost point, has shifted from where it was first laid. Boulders are visible in the sides of the pit, suggesting the structural fabric of the original passage beneath.