The enclosure, subcircular and measuring roughly 43 metres east to west and 33 metres north to south, is now defined mostly by a denuded bank, one that has been worn so low along its south-western arc that no surface trace remains at all. What endures more legibly is the external fosse, the defensive ditch that once ran around the outside of the bank, still readable in the ground from the north-east, around through the east, and down to the south-east.

Ringforts, known in Irish as raths when they are earthen rather than stone-built, were the standard enclosed farmstead of early medieval Ireland, broadly spanning the period from around the fifth to the twelfth century. Thousands survive across the country in varying states of preservation, though many have been lost to agriculture and development over the centuries. The one at Gortnagier sits in undulating grassland with boggy terrain dropping away to the south, a positioning typical of rath sites, which tended to occupy slightly elevated or well-drained ground rather than exposed hilltops. A gap in the bank at the north-east is likely modern in origin, though it may coincidentally follow the line of an original entrance, the conventional approach point for a rath of this kind.

The site's poor preservation makes it more of interest to those already attuned to reading subtle earthworks than to a casual passer-by. The fosse is the most visible feature, best appreciated from the north-eastern side where it retains some definition. The surrounding boggy ground to the south gives a sense of why this particular patch of slightly firmer, elevated grassland was chosen in the first place, a small but meaningful advantage in a wet Atlantic landscape.