From certain angles it reads as unremarkable coastline. Look more carefully, and the ground reveals something older: a fosse, the term for a man-made defensive ditch, curves around the landward side of the area, and a low outer field bank traces what was once a more deliberate boundary. Together they suggest an embanked enclosure, the kind of earthwork built to define and perhaps defend a space, though no bank survives above ground and no entrance is visible.

The enclosure was noted on the Ordnance Survey's six-inch map of 1839, which recorded an external diameter of around forty metres. What survives on the ground is somewhat smaller, approximately twenty-three metres across on a northwest to southeast axis, partly because the sea-cliff itself now forms part of the enclosure's western and northern edge. The fosse is measurably deeper on its northern arc than at the south-southeast, where it has largely silted or eroded away. The site sits below higher ground to the east and south, which would have left whoever used it overlooked from the landward side, an unusual arrangement if defence was the primary purpose. Archaeological testing carried out around 2009, roughly two hundred metres to the south and reported by Ó Drisceoil in 2012, produced no material that could be directly associated with the enclosure, leaving its date and function unresolved.