By cutting a bank and ditch across the neck of a promontory, builders could secure a triangular or finger-shaped spur of land against landward approach while the sea guarded the remaining sides. The result is a form of monument that reads as much as a statement of presence as a purely military structure.

Inishodriscol, also known as Hare Island, sits in Roaringwater Bay, a stretch of water historically associated with the O'Driscoll clan, the dominant maritime family of this part of Munster through much of the medieval period. The island's very name encodes that connection, the "driscol" element deriving directly from the family. Promontory forts along this coastline fit into a wider pattern of defended coastal sites that would have controlled fishing grounds, sea lanes, and the movement of goods along one of the more active stretches of Ireland's southern seaboard. Beyond that general context, the specific history of this particular fort, its construction date, its builders, and its use over time, remains to be fully documented.