The name itself is worth pausing over. In Irish, "inis" or "oileán" forms appear frequently in place names associated with small islands or isolated rises of ground, and "gub" likely derives from "gob", meaning a beak or projecting point of land. That combination suggests a narrow spit or small island, the kind of low, easily overlooked feature that could once have held a structure, a burial, or simply a name carried forward by local memory long after its original purpose was forgotten.

Lough Cullin is connected to the larger Lough Conn to its north, and the two together form part of a significant inland waterway system in Mayo. The area has a long history of human activity, with crannogs, the artificial or partially artificial islands built on lakes and used as defended dwelling places from the Bronze Age through to the early medieval period, recorded across the lake system. Whether Illangub represents such a feature, a natural promontory, or something else entirely is not currently possible to say with certainty from what has been made publicly available. The name, though, has survived, which is itself a form of evidence that the place once mattered to someone.