Visit today and you will find nothing. No bank, no ditch, no stone out of place. The enclosure that cartographers once thought worth recording has been entirely absorbed into the farmed landscape, leaving only its ghost on paper.

What those maps preserve is almost certainly the outline of a bivallate ringfort, a type of enclosed settlement common across early medieval Ireland in which two concentric earthen banks, separated by a ditch, defined a defended homestead. The double-bank arrangement generally signals higher status than a simple single-banked enclosure. Writing in 1903, a Costello observed the physical remains still legible enough to describe: two mounds with an intervening ditch, and along the inner face of the inner bank, several large stones still in place. Costello judged that the structure had originally been faced with boulders throughout, giving the bank a dry-stone revetment that would have made it considerably more imposing than a simple earthen rampart. By the time that observation was published, the site was clearly already diminished; in the century since, agricultural activity has removed whatever remained above ground.

There is little a visitor could usefully observe on the ground now. The value of Lisnaportagh lies less in any physical experience of the place than in what its disappearance illustrates: how thoroughly a monument that was still partially legible in the early twentieth century can be erased within a few generations, surviving only in an old map's contour lines and a brief set of notes made just in time.