The one that survives on a hilltop in Carrowcor, County Sligo, is oblong, a subtly unusual shape that sets it apart before you have even begun to read the detail of its earthworks. It sits above the confluence of the Carrowcor River and the Dunneill River, commanding the junction of the two watercourses from the western slope of the hill, though that slope has been partially quarried away, erasing whatever the fort once looked like from that side.

The enclosure measures roughly 38.5 metres north to south and 26.5 metres east to west, defined by an earthen bank that varies in width and height as it runs around the perimeter, standing taller on the exterior face to the north than to the south. A gap of about 3.2 metres on the eastern side, positioned slightly off-centre toward the south, is thought to be the original entrance. Inside, the site holds several layers of possible activity. Near the eastern bank in the northern half, there are traces of what may be a subcircular hut, the kind of modest dwelling that would have housed a farming family during the early medieval period, roughly between the fifth and twelfth centuries. In the south-western quadrant, a low bank extends about eight metres inward from the western enclosure wall, possibly the remnant of a structure built against it. There are further hints of an east-west division across the southern half of the interior, though long grass made this difficult to read clearly at the time of inspection, leaving that part of the site's internal layout unresolved.