That positioning is not accidental. The site occupies precisely the kind of elevated, well-drained vantage point that early medieval builders favoured, and the marshy terrain to the west would have served as a natural deterrent to approach from that direction.

The enclosure is roughly polygonal in plan, measuring about 60 metres east to west and 50 metres north to south, though the 1838 Ordnance Survey six-inch map records it as oval-shaped, suggesting either that the earthworks have shifted slightly in appearance over nearly two centuries or that early cartographers smoothed its outline. What defines it is a layered defensive arrangement: an earthen bank, up to 4.5 metres wide and standing between 0.8 and 1.8 metres on the exterior face, is flanked by two fosses, the ditches that in Irish earthwork archaeology typically accompany such banks. The inner fosse runs 3 to 3.5 metres wide and about a metre deep; the outer fosse is slightly narrower at 3 metres and somewhat deeper at up to 1.2 metres. Both are best preserved on the northern and western sides, where they remain steep-sided and flat-bottomed, a profile that speaks to deliberate construction rather than gradual erosion. There is one original entrance, a narrow gap of about 2.5 metres at the southern end of the east side, with a causeway left across the inner fosse to allow passage. A second, wider gap on the southern side is a modern intrusion. Curiously, there are no ancient internal features, no traces of structures or activity within the enclosed space. The field boundaries attached at the north-west and north-east, which share the same fosse-and-bank arrangement, may represent the remnants of a field system laid out at the same period, though whether that period was early medieval or earlier remains uncertain.