It is listed among Ireland's known monuments, but the specifics of what survives at ground level, how old it is, or what purpose it once served have not yet been made publicly available. An enclosure, in the broad archaeological sense, is any defined area bounded by a ditch, bank, wall, or combination of these, and such features in the Irish landscape range from prehistoric ritual sites to early medieval farmsteads to later defensive compounds. Which of these categories, if any, applies here is not yet clear from the public record.

The townland name, Oldcastle, is itself quietly suggestive. Townland names containing "castle" often preserve a memory of a defended structure, whether a tower house, a bawn (a walled enclosure attached to or surrounding a fortified house), or an earlier fortification, though the name alone is no guarantee that anything substantial remains. Mayo has a dense and layered archaeological landscape, with evidence of human activity stretching back to the Neolithic period, and enclosures of various kinds appear throughout the county. Without further detail, this particular site sits in that category of places whose presence on the map raises more questions than it answers.