The site is a coastal promontory fort, a type of defended enclosure in which a naturally protected spit or headland was cut off from the mainland by an earthwork, turning geography into fortification. Here, the defining feature is a fosse, roughly five metres wide, running roughly south-west to north-east across the landward, north-western side of the promontory, severing an area of approximately 1.2 hectares. A fosse is simply a ditch, usually dug to create both a physical barrier and a bank from the upcast material, and in this case it is no longer legible as an earthwork on the ground. It survives only as a cropmark, a faint shadow in the soil that shows up on aerial photographs when overlying vegetation responds differently to buried disturbance.

Cropmark evidence of this kind can be elusive, and this fort might have remained entirely unremarked were it not for aerial survey photography that caught the tell-tale trace of the buried ditch cutting across the headland. The promontory itself is oriented north-west to south-east, making use of the natural coastal edge to provide defence on three sides. What makes the broader landscape around Kilpoole particularly interesting is the density of prehistoric activity in the immediate area. Roughly 150 metres to the south of the promontory lies a separate enclosure, and beyond that a field containing a substantial complex of ring-ditches, at least seven of them recorded in close proximity. Ring-ditches are typically the eroded or ploughed-down remains of circular burial monuments, often Bronze Age in character, and a cluster of this size suggests the area was significant to communities over a long period. The promontory fort itself is harder to date precisely without excavation, though such sites are generally associated with the Iron Age in Ireland.