That erasure from the record makes its physical survival all the more curious. The enclosure measures roughly 65.5 metres east to west and 41 metres north to south, making it a substantial structure, and what remains of its western arc still carries real presence in the landscape.

A rath is a type of ringfort, essentially a circular or oval enclosed settlement defined by one or more earthen banks and ditches, most commonly associated with early medieval Ireland between roughly the 5th and 12th centuries. Here, the western half preserves the full sequence: an inner bank or scarp, then a fosse (a flat-bottomed or V-shaped ditch), then an outer bank beyond that. The outer bank on this site stands to an external height of around 1.5 metres and is best preserved along the west to north arc. The eastern half has been considerably reduced, its enclosing elements worn down to low undulations, possibly through centuries of agricultural activity. A faint rise in the base of the fosse at the south may be the remnant of a causeway, the original entrance point across the ditch. The interior is itself raised, with the centre sitting roughly 2 metres above the perimeter on the north-east to east side, a drop that may partly reflect a natural rise incorporated into the design. Within 10 metres to the north lies a fulacht fia, a type of prehistoric cooking site typically identified by a mound of burnt and fire-cracked stone, suggesting that human activity in this immediate area predates even the rath itself. A second rath sits approximately 230 metres to the north-east, hinting that this part of Ballyglass once supported a denser pattern of settlement than the present landscape of pasture and forestry plantation might suggest.