Peer through the displaced lintels and you can make out a stone-lined chamber below, its roof partially open to the sky, its interior beyond proper reach. The hollow that marks it is the kind of feature that most walkers would pass without a second glance.

The structure is a souterrain, a type of underground passageway or chamber built using dry-stone construction, meaning no mortar, just carefully fitted stone. Souterrains are found across early medieval Ireland, typically associated with ringfort settlements, and were used variously for storage, refuge, or ventilation of adjoining structures. This particular example is oriented northeast to southwest, measures roughly 2.5 metres in length and 1.5 metres in width, and is inaccessible in its current state. Whether its lintels, the flat capstones that once sealed it from above, shifted through ground movement or agricultural disturbance is not recorded, but their displacement is now the only reason the chamber is visible at all. The site was documented in an archaeological survey of the Ballinrobe district, covering the areas around Lough Mask and Lough Carra, published in 1994.