A narrow tongue of cliff juts out into the Irish Sea, and at some point in the prehistoric or early medieval past, someone recognised that the sea itself could do most of the defensive work. The result is a promontory fort, a type of enclosure in which a headland is sealed off from the mainland by one or more earthen banks and ditches, leaving the sheer coastal drops to guard the remaining sides. What stood inside, and who built it, remains an open question for Dunbur Head.Promontory forts of this coastal kind are found at intervals along the entire Irish seaboard. Their construction is generally associated with the Iron Age, though some were reused or modified well into the early Christian period. The Wicklow coastline, with its succession of headlands running south from Bray, offered numerous such opportunities, and Dunbur Head sits within a stretch of coast that would have seen both coastal traffic and the kind of territorial thinking that made defensible high ground worth the labour of construction. Without detailed excavation records available for this particular site, the specifics of its date, the number of its ramparts, and any evidence of structures within the enclosure remain undocumented in the public domain.What is visible today is largely a matter of topography and inference. The headland itself retains its form, and the relationship between the landward approach and the cliff edges that once made the site attractive for fortification can still be read in the landscape, if you know what pattern to look for.