The raised oval platform, measuring roughly 31.5 metres east to west and 27.4 metres north to south, is what remains of a rath, the Irish term for a ringfort, which was typically a circular or oval enclosure of earthen banks used as a farmstead during the early medieval period, broadly between the fifth and twelfth centuries. What makes this particular example quietly arresting is how much of it has retreated into the landscape: the enclosing bank and its accompanying fosse, a shallow external ditch dug to reinforce the boundary, are now only traceable along the southern arc, from east-southeast around through south to west-southwest.

The most legible feature that survives is a break in the bank on the east-southeast side, accompanied by a causeway crossing the fosse. This is almost certainly where people once entered and left the enclosure in daily life, a threshold that has outlasted the dwelling it served by many centuries. Ringforts of this kind were once extraordinarily common across Ireland, with estimates suggesting tens of thousands originally dotted the countryside, each representing a single farming household and its livestock. The name Lisnaclea itself echoes this past, with the element "lis" being an Irish word for a ringfort or enclosure, suggesting the site was recognised and named by the community long before any modern survey took an interest in it.