Each one has been cut off from the land by an earthen bank and an outer fosse, the term for the ditch dug to reinforce such a barrier, yet the interiors enclosed are remarkably modest, none longer than eleven metres or wider than seven. Whatever was being defended here, it was not a large settlement.

What makes this complex genuinely unusual is the relationship between the three headlands and the broader promontory behind them. When Casey surveyed the area in 2002, the evidence suggested that Parkmore Point itself had once been enclosed by a series of banks and ditches, making the three smaller headlands subsidiary enclosures within a larger fortified system. The remains of the main enclosing bank across the point are still visible between two of the smaller headlands. A promontory fort, in general terms, is a defended enclosure that uses the natural shape of a coastal headland to reduce the amount of man-made barrier required, with the sea doing much of the defensive work. Here, sheer cliffs flanking each headland make the sea entirely inaccessible from the interior, so the enclosures were sealed on all sides. The enclosing elements themselves are modest, between two and three and a half metres wide and reaching at most a metre in height from the base of the fosse to the top of the bank, but their multiplication across a single point gives the site an organisational complexity out of proportion to its modest scale. The surrounding land remains, as it likely was in the past, fertile grazing ground.