The site is accessed via a narrow neck of land that's cut through by what appears to be an ancient defensive ditch, though any accompanying bank has long since disappeared. Until the early 1900s, the promontory was dotted with several huts, but these were cleared away, leaving the interior as a gently sloping grassland that tilts eastward, with traces of more recent agricultural use still visible.

About 324 metres north of the southern tip of The Doon, the original defensive perimeter can still be traced. Here, a low earthen bank survives, measuring roughly 0.7 metres wide at its top and 1.5 metres at its base, standing just 0.2 metres high on the interior side. Running alongside it is an outer fosse, or defensive ditch, about a metre wide and 0.2 metres deep. This earthwork stretches for 50 metres from east to west, effectively cutting off the headland and creating what archaeologists classify as a promontory fort; one of many such coastal defences found along Ireland's Atlantic shores.

Near the northern edge of the fort stands a small, curious earthen mound with a slightly hollow summit, rising 0.4 metres high with a top diameter of 2.4 metres and a base spanning 4.6 metres. Local tradition holds that this modest mound marks an ancient grave or burial site, adding another layer of history to this windswept promontory. Combined with the burial mound at Málainn Bhig in County Donegal, these sites offer glimpses into how Ireland's coastal communities once lived, defended themselves, and honoured their dead on these dramatic Atlantic headlands.