The principle is straightforward: where a finger of land juts out into the sea, the builders needed only to construct a rampart or ditch across the narrow neck to create an enclosure defended on three sides by water and cliff. The sea does much of the work. These structures are found all around the Irish coastline, and while many date to the Iron Age, some continued in use, or were freshly built, into the early medieval period.

The Killough example sits within a wider Cork landscape that is dense with such sites. Cork's fractured, heavily indented coastline, full of headlands and narrow peninsulas, lent itself naturally to this kind of fortification, and the county preserves a considerable number of examples in varying states of survival. Some retain clear earthen banks and ditches cutting across the promontory neck; others have been reduced by erosion, agriculture, or the slow collapse of cliff edges over the centuries. Without further detail on this particular site, it is difficult to say precisely what survives at Killough, but the location itself, a named coastal point in County Cork, suggests a headland where the basic geometry of sea and land once made defence possible with relatively modest effort.