That depression is the only surface evidence of what archaeologists suspect was once a souterrain, an underground passage or chamber typically constructed during the early medieval period, often used for storage, refuge, or concealment. The collapse of the roof, whether stone-lined or timber-framed, would naturally leave exactly this kind of subtle hollow, easy to overlook and easy to misread as nothing more than a trick of the terrain.

The site sits within a ringfort, the most common archaeological monument type in Ireland, of which tens of thousands survive in varying states of preservation. These were enclosed farmsteads, usually dating from roughly the sixth to the twelfth century, their interiors protected by one or more earthen or stone banks. Souterrains were frequently built inside ringforts, accessed from the interior and occasionally connecting to the exterior through narrow, deliberately awkward passages. At Laharan, the relationship between the enclosure and its possible underground feature follows that familiar pattern, with the depression located close to the centre of the fort rather than at its edge.