They have since been blocked, and what lies beneath them is a souterrain, an underground stone-lined passage or chamber constructed during the early medieval period, typically as a place of refuge, storage, or concealment. The blocked mouths are now the most visible clue that anything is there at all.

The site was observed by P. J. Hartnett in 1939, when he recorded the three openings in their original, unblocked state. The souterrain sits within a ringfort, the type of circular enclosure defined by an earthen bank and ditch that served as a farmstead for much of early medieval Ireland. Finding a souterrain inside a ringfort is not unusual in itself, as the two features frequently occur together across the country, but the presence of three distinct openings arranged in a line is a detail worth noting. Hartnett's record, published in 1939, remains the primary observational account of the feature before the openings were closed off.