What looks like a pair of distinct openings is actually a single underground structure, a souterrain, entered from two points that have since diverged in fortune: the western access remains open, its roof lintel displaced but passable; the eastern one has been quietly covered over. At ground level, the whole thing reads as a roughly L-shaped depression in the earth, the kind of feature that is easy to walk past without registering what lies beneath.

A souterrain is a drystone-built underground passage, typically associated with early medieval settlements and used variously for storage, refuge, or ventilation of food supplies. This one sits within the south-western quadrant of a rath, a circular earthwork enclosure of the kind that served as a farmstead across Ireland from roughly the fifth to the twelfth centuries. The souterrain itself extends to over twenty-one metres in total, comprising a long passage running roughly west-north-west to east-south-east at thirteen metres, and a shorter passage of eight metres branching off at the eastern end and running north-north-east to south-south-west. The long passage is reasonably substantial, around 1.75 metres wide and 1.3 metres high, with an air vent visible in the north-western side-wall near its western end. The shorter passage has largely collapsed, and the junction between the two arms has also gone, which explains why early mappers read the two access points as separate features entirely rather than the two ends of one connected system.