That narrow corridor of eroding ground is the only way onto an anvil-shaped promontory, and it is there, strung across this precarious threshold, that the remnants of a coastal promontory fort survive in rough pasture at the foot of a steep north-facing slope.

A promontory fort is exactly what the name suggests: a naturally defensive position, usually a headland or cliff-edge, where people cut off access from the landward side using banks and ditches rather than relying on elaborate stone construction. At this site, three earthen banks and three corresponding fosses, the shallow ditches dug to reinforce those banks, cross the neck in sequence. The banks reach a maximum width of three metres and a height of just 0.65 metres, and the fosses are similarly modest in their surviving dimensions. Three lines of defence across a corridor barely wide enough for a cart speaks to the anxiety that shaped the fort's design as much as any practical military calculation. The site sits within the Irish-speaking community of Lios Ó Móine on Clear Island, one of the most remote inhabited islands off the Cork coast, and the Irish-language placename of the headland itself, Stuckaunfoilnabena, suggests the kind of deeply local knowledge that has kept the feature in living memory even as the earthworks have quietly eroded.

Surveyors who visited the site noted that further physical examination of the remains was not possible for safety reasons, a detail that gives some sense of the exposure and instability of the ground. The combination of the collapsing neck of land, the Atlantic on three sides, and the steep slope behind means the fort is as much a landscape experience as an archaeological one.