The result is a promontory fort, a class of site found in scattered numbers around Ireland's coastline, where a narrow land connection to a headland was blocked off with earthworks to create a naturally fortified enclosure. What survives at Broomhill is subtle: two low earthen banks, each only around fifty centimetres high, separated by a shallow fosse, the old term for a defensive ditch. A causeway cuts through the middle of these enclosing elements, suggesting a deliberate entrance rather than a later breach, and a slight bank traces the outer edge of the promontory itself. Just inside the entrance, the faint circular outline of a hut-site, about three metres across, sits close enough to the threshold that it may once have served some kind of gatekeeping function.

The full sixty-metre length of the headland slopes gradually down toward the shore, flanked on either side by sheer cliff. Several further earthworks are visible along the northern cliff edge, though their precise character is difficult to read. The defences have not been helped by later interference: an earthen bank associated with the Land Commission, the body that oversaw the redistribution of agricultural land in Ireland from the late nineteenth century onward, runs along the cliff edge outside the fort and has disturbed the original layout to some degree. Casey, who surveyed the site in 2001, recorded all of this against a backdrop of rolling fertile pasture, the landscape around the fort showing little sign that anything unusual lies at its edge.