The site is a raised D-shaped enclosure, roughly 100 metres north to south and 115 metres east to west, sitting on flat, poorly drained ground. An earthen bank, still standing around 1.5 metres high and 2 metres wide, runs around its perimeter, with a fosse, a defensive ditch, cut just beyond it. The whole thing is so thickly overgrown that close inspection is essentially impossible, and there is no visible entrance feature anywhere along its circuit.

Enclosures of this kind are a familiar, if still debated, feature of the Irish landscape. They are generally thought to date from the early medieval period, when enclosed farmsteads or settlement compounds were common, though some examples have earlier or later origins. What makes this particular site quietly interesting is the layering of time visible even in its overgrown state. Faint traces of what appears to have been an outer bank survive, but much of it has been absorbed into or replaced by a nineteenth-century drystone wall, most legible at the southern side. That wall is itself now presumably as weathered as everything else, a later hand reusing an ancient boundary without necessarily knowing, or caring, what it was. The name Drumnamahaneisland, with its suggestion of an island feature in the drumlin or ridge landscape, may also hint at how this slightly elevated ground was once perceived among the surrounding wet and boggy terrain.

Scohaboy Bog presses close to the southern edge of the enclosure, which likely helped preserve the earthwork by making the land unattractive for deep agricultural disturbance. The dense vegetation that now makes examination so difficult is, in its own way, a kind of accidental protection.