This is a souterrain, an underground stone-lined tunnel or chamber built during the early medieval period, typically as a place of refuge, cool storage, or concealment. Most souterrains survive only as anomalies in the soil, detectable by subsidence or the faint outline of disturbed ground. This one announces itself a little more directly, with a scatter of exposed flagstones near the surface, though there is precious little else left to see.

Around 1937, a researcher named Hartnett recorded the site and noted that while the cave itself had already collapsed, the flagstone roofing was just visible near the centre of the ringfort it sits within. A ringfort, to use the general term, is a roughly circular enclosure defined by an earthen bank or stone wall, common across Ireland from the early medieval period and typically associated with a farmstead or settlement. The souterrain would originally have opened from inside this enclosure, providing the occupants with a place to retreat to or store goods. By the time Hartnett visited, the entrance was blocked and the structure had largely given way. It has not improved since.