It sits in ordinary pasture, unremarkable to the casual eye, yet the ground beneath the grass preserves the outline of an enclosure whose original purpose is no longer certain. The earthen bank survives to a height of only about sixty centimetres, and its southern arc has become so degraded as to be almost illegible on the ground. What remains legible is a deliberate break in the bank on that same southern side, where the earthwork turns and runs northward, back into the interior of the enclosure itself.

Circular earthen enclosures of this kind are a common, if not always well-understood, feature of the Irish landscape. They range from ringforts, which served as enclosed farmsteads during the early medieval period, to earlier ritual or boundary monuments, and distinguishing between them without excavation is often impossible. What makes the Knocknadrimna example quietly interesting is that particular southern entrance arrangement, where the bank does not simply terminate but bends inward, a configuration sometimes associated with controlling the movement of people or animals through a defined threshold. The site commands an open view to the west, a quality shared by many enclosures whose placement seems to have been chosen as much for visibility and prospect as for any purely practical reason. It was recorded as part of an archaeological survey of the Ballinrobe district, including the Lough Mask and Lough Carra area, compiled by D. Lavelle and published in 1994 by the Lough Mask and Lough Carra Tourist Development Association.