What was once a roughly circular earthwork enclosure, some 39 metres across at its widest, raised on a gentle rise with open views across undulating pasture, has been so thoroughly absorbed into the working landscape that aerial photography shows nothing of it at all. That complete disappearance is, in its own quiet way, the most interesting thing about it.

The fort was clearly visible on the Ordnance Survey six-inch map of 1837, drawn as a circular enclosure whose northern edge had already been pressed into service as a field boundary. By the time the revised twenty-five-inch map was produced in 1913, only an arc of raised ground, a scarp roughly 29 metres long on the eastern side, survived to mark what had been there. A description from 1970 records the monument in its diminished but still legible state: an earth and stone bank on the eastern arc, steepened in relatively modern times, a faint scarp to the west, and cultivation ridges running east to west across the interior. At the centre, a rectangular house site was still discernible, suggesting the enclosure had been reused for settlement at some point after its original construction. Ringforts, which are the most common monument type in the Irish countryside, were typically built during the early medieval period as enclosed farmsteads, defined by one or more earthen banks and ditches. This one at Killahugh had been quarried heavily on its southern side, its perimeter levelled across most of its circuit, and its original entrance erased entirely. What the 1970 observer could still trace in the field has since been lost altogether.