2 metres, to make crossing it a genuinely awkward prospect. That is rather the point. The fosse, as such a defensive ditch is termed, was designed to slow or deter intruders, and at Ballynacragga it survives with enough integrity to give a real sense of how seriously its original occupants took that function. What makes this particular site quietly interesting is its double-bank arrangement: two concentric earth-and-stone rings, one inside the other, with the ditch running between them. A ringfort or rath with bivallate defences of this kind was generally associated with someone of higher social standing than the single-banked norm, suggesting the enclosure was once home to a family of some local consequence.

The site was recorded and compiled by Denis Power, with survey notes uploaded in August 2011. The roughly circular interior measures approximately 32 metres north to south and just under 29 metres east to west, sitting in undulating pasture broken up by marshy ground and rock outcrop. The inner bank reaches an external height of 1.8 metres in places, while its southern side is noticeably wider and flat-topped, likely because material was pushed against it when a later field boundary was constructed nearby, truncating the outer bank between the south-east and south-west. There are gaps in both banks at the east and west, and while the eastern gaps simply interrupt the earthworks, only the western gap aligns with a causeway across the fosse, suggesting it was the original entrance point. The outer bank is less distinct towards the north and east, and a further gap at the north-east appears to be the result of cattle wearing their own route into the interior.

The interior itself is level and under pasture, which keeps it accessible underfoot but also means the earthworks are best appreciated by walking the perimeter rather than standing at the centre. The fosse is boggy in sections, so stout footwear is advisable regardless of season, though drier months make the outer bank easier to trace where it fades at the northern and eastern sides. The surrounding landscape of marsh, rock, and rough grazing is itself characteristic of this part of Limerick, and the way the later field boundary cuts across the south of the monument is a useful reminder that working farmland has been reshaping these sites, incrementally and without ceremony, for centuries.