It is, in fact, a pond barrow, a type of prehistoric burial monument defined not by a mound rising above the landscape but by the opposite: a circular, saucer-shaped depression sitting within an enclosing bank, giving the whole thing an inverted, bowl-like profile. This one measures roughly 12.8 metres across the central hollow, with the surrounding earthen and stone bank running nearly six metres wide and still standing about 0.45 metres high. Beyond the bank, a fosse, essentially a broad outer ditch, originally completed the circuit.

Pond barrows are among the less common forms of prehistoric funerary monument found in Ireland and Britain, and their precise ritual function is not always well understood. What survives at Lisfarrell tells a quiet story of gradual erasure. Along the south-south-west to west-north-west arc, the outer face of the bank and the fosse have been absorbed into a field boundary, their prehistoric geometry quietly repurposed for agricultural convenience at some unknown point in the past. On the opposite side, from east around to south-west, the fosse has been infilled to the point where its outline is barely legible in the ground. The original entrance to the enclosure, if there was a formal one, can no longer be identified.

What remains is modest by any measure, a shallow depression in damp pasture, a low bank of earth and stone, fragments of a ditch. But the combination of the waterlogged setting and the pond barrow form, with its deliberate inward hollow, gives the site an unusual character among the prehistoric monuments of the Irish midlands. It sits in the landscape doing very little to announce itself, which is perhaps the most honest thing that can be said about it.