It is the kind of structure that could be walked over without a second thought, barely half a metre high and two metres wide, but it marks what may be a promontory fort, a class of defensive enclosure in which a natural headland or spit of land is sealed off by a constructed barrier, turning geography itself into a wall. What makes this particular example quietly arresting is not what has survived, but what is disappearing.

The promontory the rampart was built to enclose is in serious trouble. Rising sea levels and repeated storm surges have eaten into the southern tip of Inishgort to the point where storm beaches on the western and eastern flanks have nearly converged, leaving only a thin central strip of vegetation between them. The southern extremity is now almost entirely cut off from the rest of the promontory. No ditch accompanies the rampart, which is unusual for this type of fort, where a cut trench often reinforced the defensive line. Whether its absence means one was never dug, or simply that no trace survives, is not clear. The site was recorded by M. Gibbons, who also documented a cashel (a stone-walled ringfort) roughly 42 metres to the south, and a midden, a deposit of domestic refuse that can indicate long-term settlement or seasonal occupation, about 73 metres further on. The clustering of these features suggests the southern end of Inishgort was, at some point, a place worth defending and inhabiting.

What is left of the promontory is now a race against the Atlantic. The rampart itself persists, low and unassuming, but the land it was built to protect is being gradually claimed. Visiting the island offers the unusual experience of looking at an ancient boundary marker while watching the boundary it defines slowly cease to exist.