The structure is known as a rath, the Irish term for a ringfort, a type of enclosed farmstead typically built during the early medieval period, between roughly the fifth and twelfth centuries, and once numbering in the tens of thousands across Ireland. What makes Lisduff quietly compelling is the degree to which the land has quietly reclaimed it. Cattle paths wind into the interior and simply stop, blocked by fallen trees. The enclosing bank, where it survives most visibly on the south-west to north-west arc, still rises to an external height of about 1.5 metres, but on the north-west to north-north-east stretch it has been reduced to something barely distinguishable from the surrounding ground.

The monument appears on all the Ordnance Survey historic mapping of the area and was named Lisduff Fort on both the 25-inch series and the 1921 edition of the six-inch map, giving it a recorded presence stretching back well into the nineteenth century. The enclosure is defined not only by its earthen bank but also by a steep scarp on the north-east to south-east side, dropping about 1.1 metres, which would have contributed to the defensive or boundary character of the site. A possible fosse, a term for an external ditch typically dug to heighten the perceived height of the surrounding bank, runs along the west to north-west, though it is now shallow and choked with vegetation. A wide gap of around four metres on the north-north-east to north-east is likely an original entrance. Higher ground to the south-west, west, and north-west overlooks the fort, suggesting the site was chosen for its position within a local landscape rather than for any commanding view of its own.