A promontory fort works by letting the sea do most of the defensive work: a headland jutting into water is naturally protected on three sides, and the builders needed only to construct a bank, ditch, or wall across the narrow neck of land at the landward end to create an enclosure that was genuinely difficult to approach. The result was a fortified space that could serve as a refuge, a stronghold, or a high-status settlement, depending on the period and the community in question.

These coastal forts are found all around the Irish seaboard, and while many have been dated to the Iron Age, some were in use across a much longer span of time. Clare's coastline, exposed to the Atlantic and edged with dramatic geological features, contains several examples, and the one at Corbally is among those that sit quietly in the archaeological record without a great deal of individual documentation attached to them yet. The source material for this particular site remains sparse, which makes it difficult to say with confidence when it was constructed, how extensive its earthworks were, or what role it may have played in the local landscape.