At roughly nineteen metres across, it is easy to mistake for just another field boundary, which is precisely what makes it curious. The wall that encloses this space is built in the same rough manner as everything around it, and yet the circle it describes is deliberate, ancient, and almost certainly predates the agricultural grid that now surrounds it.

Circular enclosures of this kind appear throughout Ireland and are generally understood to be the remains of early settlement or activity, often associated with the early medieval period, when ringforts, the most common monument type in the Irish countryside, served as enclosed farmsteads for a family and their livestock. A ringfort typically consists of a circular bank and ditch of earth, but in areas where stone was more available than soil, the enclosing element was built in dry stone, producing what is sometimes called a cashel or caher. The Killimor example, recorded in a 1994 archaeological survey of the Ballinrobe district including the Lough Mask and Lough Carra area, fits broadly within this tradition, though its rough construction and absorption into the surrounding field pattern make it difficult to date or interpret with certainty. What survives is the footprint: nineteen metres of enclosed space, defined by a wall that the landscape has nearly swallowed.