A souterrain is an underground stone-lined passage, usually associated with early medieval settlement in Ireland and thought to have served as a place of refuge, storage, or both. Finding one positioned so deliberately within a dwelling structure gives this particular site a quietly purposeful character.

The broader enclosure is a cashel, a circular stone-walled fort of the kind common across the west of Ireland from the early medieval period onwards. The hut itself sits within the cashel's north-eastern quadrant. Descriptions of the site have varied slightly over the decades. An OPW survey in 1983 characterised it as a square enclosure with the souterrain opening at its centre. A later survey of the Ballinrobe district, carried out by Lavelle in 1994, recorded it instead as circular, measuring approximately 10.5 metres in diameter and surviving to a height of around 0.6 metres. Whether that discrepancy reflects changes to the structure over time, differing methods of measurement, or simply two surveyors seeing slightly different things, the core feature remains consistent across both accounts: a habitation space built, seemingly intentionally, around access to an underground passage.