You would not know it was there if you were standing on top of it. The only evidence of its existence comes from a single aerial photograph taken in 1973, in which the outline of the feature resolves itself clearly enough from above, even as it remains entirely invisible at ground level.

Enclosures of this kind, when they survive in the Irish landscape, are generally understood as the remains of ringforts, the circular earthwork settlements that were the dominant form of rural habitation during the early medieval period, roughly the fifth to the twelfth centuries. They were typically defined by one or more earthen banks and ditches, and served as farmsteads for single family groups. At Coomnakilla, the planting of a coniferous forest over the site has both obscured whatever surface traces may once have existed and, ironically, helped preserve the underlying archaeology from more destructive land use. The 1973 photograph also shows a second possible enclosure lying approximately thirty metres to the north-north-west, which raises the prospect of two such features in close proximity, though the second remains unconfirmed.