That combination, an earthen rampart with an external fosse cut into the ground in front of it, was enough to seal off the neck of the promontory from the landward side, leaving the sea to do the rest of the defensive work. The fosse, a term for a defensive ditch, runs across the approach and deepens noticeably as it nears the northern cliff edge, as though whoever dug it understood exactly where the ground was most exposed.

A survey carried out in 2002 by Casey recorded the surviving earthworks in some detail. The bank averaged around a metre in height and roughly 2.3 metres in width, while the fosse measured between three and four metres across and sat about 80 centimetres below the level of the outer field. Two gaps interrupt the line of the bank; one sits close to the southern cliff, the other roughly eight metres from the northern edge. Either could represent the original entrance, though the question remains open. Along the southern cliff edge, a faint raised lip hints at the former line of a perimeter bank, now largely lost. The headland itself is about 75 metres long, west-facing, and flanked on both sides by sheer cliffs that drop to a shore described as inaccessible from within the fort. Whatever the promontory was used for, escape by sea was not an option.

Promontory forts of this kind are scattered along the Irish coastline, particularly in Munster, and their dates of construction and use vary considerably, with many belonging to the Iron Age or early medieval period. At Meenogahane the earthworks are modest in scale but remarkably legible, the basic geometry of bank, ditch, and cliff-defended headland still readable in the landscape even after centuries of weathering.