Rather than constructing defences on all sides, the builders of such forts let the sea do much of the work, throwing up a bank or wall across the landward neck of a promontory and relying on the cliffs and water to secure the rest. It is an arrangement that speaks to a particular kind of practical ingenuity, and it is found at dozens of points around the Irish coastline, though each site carries its own particular character depending on the rock beneath it and the water around it.

Illaunmore's fort belongs to a broader tradition of coastal promontory fortification that was practiced in Ireland from the Iron Age onwards, and in some cases into the early medieval period. The precise dating and history of this particular example remain to be fully documented, which is itself a reflection of how many such sites exist along the Irish coast, quietly occupying their headlands and island edges, awaiting closer attention. What is known is the place itself: a small island off County Cork, where someone, at some point, chose this spot as worth defending or inhabiting, and shaped the ground accordingly.