A small cluster on the Mayo shore carries a rather different name, one that signals a grimmer function: the Prison Islands. The name alone raises questions that the landscape does not immediately answer, since there are no obvious walls or gatehouse foundations visible to the casual eye, and the islands sit quietly among the reeds like any others on this vast lake.

The name almost certainly points to a period when island detention was a practical, if harsh, solution to the problem of confinement. Across Ireland, loughs and coastal inlets were occasionally used in this way, with water serving as a ready-made perimeter. Lough Corrib sits on the border between County Galway and County Mayo, and the western reaches, where these islands lie, were historically remote enough to make escape a serious undertaking. Whether the confinement here was administered by a local Gaelic lord, a colonial administration, or some later authority is not presently documented in available sources, and the specific history of the site remains genuinely obscure. That obscurity is itself part of what makes the name so arresting: it preserves the memory of something that happened here without quite telling us what.