The designation alone, an enclosure, covers a wide range of human-made structures, from early medieval ringforts that once enclosed a farmstead and its inhabitants to prehistoric ceremonial boundaries whose purposes remain a matter of interpretation. That ambiguity is, in its own way, part of what makes such sites worth pausing over.

An enclosure, broadly speaking, is any roughly circular or oval area defined by a bank, ditch, wall, or combination of these features. In an Irish context they appear across thousands of years of settlement, and the county of Mayo has no shortage of them, scattered across bogland, drumlin country, and coastal margins. Bloomfield itself is a townland name with a planted, post-medieval ring to it, the kind of name applied during periods of estate reorganisation, which adds a further layer of historical sediment to the ground beneath it. Whether the enclosure predates that naming by centuries or millennia is precisely the sort of question that currently lacks a published answer.