The rath at Cabraghkeel, Co. Sligo, has lost both. What remains is a low circular platform, roughly 23 metres across and less than a metre high, sitting on a gentle rise about 200 metres from the eastern shore of Killala Bay. No bank survives, no fosse, and the original entrance is no longer readable in the ground. It is the kind of site that asks a good deal of imagination from anyone trying to reconstruct what once stood here.

What gives the site its particular interest is not what survives above ground but what lies beneath it. Within the interior of the circular area is a souterrain, an underground passage or chamber, typically stone-lined, that was used in early medieval Ireland for storage, refuge, or both. Souterrains are common companions to ringforts, often built into the body of the enclosing bank or accessed from within the enclosed space, and their presence frequently outlasts the earthworks above them. Here, where the bank has been partially levelled, possibly through centuries of agricultural use, the souterrain endures as the most concrete evidence that this was once a place of some domestic significance. The site sits in a quiet coastal position, with Killala Bay lying close to the west, a location that would have made it both exposed to Atlantic weather and well placed to watch the water.