What it marks is a promontory fort, a type of enclosure in which a narrow headland is cut off from the mainland by a series of earthen banks and ditches rather than by walls alone. The unusual element here is that most of the promontory itself has since eroded away, leaving the defensive earthworks largely intact while the land they were built to protect has vanished.

What survives is a double line of defences, each consisting of a fosse, which is a ditch dug to impede approach, backed by a raised bank. The outer fosse sits roughly 1.2 metres below the level of the surrounding ground and is 2 metres wide; the bank behind it rises to an external height of 0.8 metres and spreads about 6 metres at its base. The inner bank is considerably more substantial, standing 3 metres high externally with a base width of around 5.6 metres. The banks and fosses curve outward toward the landward side, which is the usual arrangement for this kind of promontory defence. A causeway to the south may mark where an entrance once stood. Immediately to the south-west sits a small semi-circular stone hut, measuring 3.7 metres north to south, with walls surviving to a height of 0.4 metres and an opening of around 2 metres on its southern side. Whether this structure belonged to the same occupation as the fort, or represents a separate episode of use, is not certain, though the proximity invites the connection. The survey compiled by C. Toal for the North Kerry Archaeological Survey, published in 1995, provides the detailed measurements on which this account draws.