A rath is an early medieval ringfort, typically a circular or oval earthen bank surrounding a homestead, and thousands of them survive across Ireland in various states of preservation. This one does not. No visible surface trace remains, and what was once a defined enclosure measuring roughly 40 metres north-east to south-west and 32 metres north-west to south-east has been absorbed entirely into the surrounding fields.

The fort's existence is known almost entirely through successive layers of cartographic record. When the Ordnance Survey produced its six-inch map in 1838, the enclosure was marked as a clear oval feature on that hummock. By the time a more detailed 1:2500 plan was surveyed between 1912 and 1916, the fort itself had diminished to a curved line of hachures, the mapmakers' shorthand for a slope or earthwork, running from south to north-west. A further revision in 1945 shows a field boundary curving in a way that probably traces the old outline, the enclosure by then surviving only as an organisational memory in the landscape, its shape quietly preserved in the way someone had decided to divide the land. Each successive map catches the fort at a different stage of erasure.