That much is certain. Beyond the bare fact of its existence and its location, the record is almost entirely silent, which is itself a curious condition for a monument old enough to have been formally noted and classified. Earthworks, as a category, cover a wide range of human-made landscape features: raised banks, enclosures, ditches, and platforms that were shaped from the ground itself, most often during the prehistoric or early medieval periods in Ireland. They survive because earth, left undisturbed, endures. What purpose this particular example served, who made it, and when, remains formally unrecorded in any publicly available form.

Barnasrahy sits in a county whose landscape carries an unusual density of ancient remains, from the megalithic cemetery at Carrowmore to the passage tombs above Strandhill, all set beneath the flat-topped limestone bulk of Knocknarea. Sligo's terrain, shaped by glacial action and underlain by carboniferous limestone, has preserved earthworks and other monuments across its fields and boglands with remarkable consistency. An earthwork in such a landscape might mark anything from a ringfort enclosure, a type of circular farmstead common in early Christian Ireland, to a field boundary of much earlier origin, or the remnant of some now-unreadable ceremonial or defensive arrangement. Without further documentation, the Barnasrahy earthwork sits in the record as a placeholder, a shape in the ground waiting for closer attention.