The ground rises almost imperceptibly into a raised oval platform, roughly 63 metres east to west and 46 metres north to south, its edges defined by a low scarp between one and one point eight metres in height. This is the kind of monument that makes itself known through measurement rather than spectacle, a shape in the land that only declares itself once you know what you are standing inside.

A report filed in 1976 recorded details that are no longer legible at ground level. At that time, a shallow external fosse was still traceable, a fosse being a ditch dug around an enclosure for defence or demarcation, and an entrance feature was noted at the south-east. More intriguing still, two possible house sites were identified, one near the centre of the interior and one towards the south-east. These kinds of enclosed settlements, broadly described as ring forts or raths, were the dominant form of rural habitation in early medieval Ireland, typically home to a single farming family and their livestock. The oval platform at Ballybranigan fits broadly within that tradition, though without excavation the date and precise character of the site remain open questions. Whatever the 1976 survey could still detect has since been lost to view, absorbed back into the surface of the field.