A souterrain is an underground stone-lined passage, typically associated with early medieval settlement in Ireland, and often interpreted as a place of refuge, storage, or both. This one stretches to more than sixteen metres in total length, though most of it can no longer be entered.

The passage follows an L-shaped plan. The longer arm, running roughly north to south at around ten metres, announces itself above ground as a combination of collapsed earth over six metres and a slight but noticeable rise for the remaining four. The shorter arm, extending east to west off the southeast end of the long axis, runs for about six metres. It is through a gap at the western end of this shorter section that a visitor might catch a glimpse inside, the only accessible view of what remains. The rath within which it sits, a type of circular earthwork enclosure used as a farmstead during the early medieval period, would once have formed the domestic and agricultural world to which this souterrain was attached. The two features together suggest a settlement of some substance, even if little now remains visible above ground beyond earthwork and collapse.