The raised circular interior, measuring just under 23 metres in diameter, retains a legible outline even where the bank has been levelled by centuries of agricultural work. Only the arc from north-north-west around through north to east survives as a substantial earthen bank, accompanied by a wide, shallow fosse, the ditch that would originally have reinforced the boundary between the enclosed space and the surrounding ground.

This is a rath, the Irish term for a ringfort, the most common monument type in the Irish countryside. Raths were typically constructed during the early medieval period, roughly between the fifth and twelfth centuries, and served as enclosed farmsteads for individual families or small communities. The earthen bank and fosse combination was a statement of status as much as a practical boundary. At Cornacarrow, a report compiled by the Office of Public Works in 1969 noted that the original entrance to the enclosure may have been positioned at the south-south-east, a placement that would have been deliberate, likely oriented to make use of morning light or to face away from prevailing winds. That detail, recorded decades ago, remains the clearest piece of evidence about how people once moved in and out of the space.