The depression, measuring roughly 7.5 metres on its longer axis and sinking about a metre deep at its western end, marks the roof of a souterrain, an underground structure of the kind built in early medieval Ireland, typically consisting of dry-stone passages and chambers constructed without mortar. These underground spaces served various purposes, including storage, refuge, and possibly ventilation for adjacent settlements, and they are often found in close association with the enclosures that once surrounded farmsteads and minor lordly residences.

This particular souterrain sits in the north-eastern quadrant of a rath, the term for a roughly circular earthen enclosure that formed the basis of many early Irish settlements. The rath itself is a separate recorded monument, and the two features together suggest a site of some domestic or social significance in the early medieval period. Local information indicates that beneath the sunken ground lies a passage leading to a chamber, both built in dry-stone construction, though the interior has not been fully investigated and much of what is known comes from surface observation and oral knowledge passed down in the area. The site holds the status of a National Monument in State care.