A circular enclosure, roughly 35 metres in diameter, once occupied this ground. Today, nothing of it can be seen. The grass grows over it as if it were never there.

What we know comes from the first edition of the Ordnance Survey six-inch map, one of the great documentary achievements of nineteenth-century Ireland, which recorded features of the landscape, including earthworks and enclosures, that were already fading at the time of survey. Circular enclosures of this kind are generally understood to be the remains of early medieval settlement, the banks and ditches of a ringfort, a type of enclosed farmstead that was once common across the Irish countryside and numbered in the tens of thousands. The Mullaghmore example, catalogued with a diameter of approximately 35 metres, sits at the smaller end of that range. At some point between the mapmakers passing through and the present day, whatever surface trace remained was levelled, absorbed into the agricultural land around it.