A rath, as these earthwork ringforts are known, was typically a circular or oval enclosure defined by an earthen bank and ditch, used as a farmstead or defended residence during the early medieval period. This one sits so low in the grass that it is easy to walk past without quite registering what you are looking at, yet its proportions, roughly 24 metres by 19 metres, and the remnants of limestone block facing still visible along its outer bank, speak to something carefully made.

The enclosure is defined by a grass-covered bank, between 1.7 and 2 metres wide, which is almost flush with the interior ground level on the inside but drops away slightly on the outside as a low scarp. Along the north-east to south-east arc, large limestone blocks, one to two courses high, survive as external facing, and a few stones protruding from the inner face of the bank to the north-north-east suggest the stonework was once more extensive. A possible fosse, a shallow defensive ditch, runs along the south-west to north-west of the enclosure, and a low outer bank is still faintly readable as a broad undulation in the turf. Both of these outer elements are cut off abruptly to the north-east, where a later field fence has been driven straight through the monument. Inside, the south-west quadrant sits slightly higher than the rest of the interior, defined by a low scarp running about 12 metres through the enclosure before fading out. Whether this raised platform represents the ghost of a hut site or the remains of a field bank that once divided the rath is genuinely unresolved. Eight metres to the south-west, a small semi-circular feature, just two metres across and defined by its own sod-covered bank, contains a heap of partly buried stones; its date and purpose remain unknown.

Coney Island is accessible on foot across the strand at low tide from the Rosses Point area, which makes timing your visit a practical matter rather than a casual one. The rath sits in working pasture on the headland, with open water visible on three sides, and the outer banks read best from a little distance, where the gentle swell and dip of the ground becomes legible against the flat light of an overcast day.