A modern field boundary runs straight through the circular enclosure from north to south, bisecting what was once a unified space, while a stream cuts off a further seven metres of the northern side. The result is that a monument originally about 31 metres in diameter now survives in pieces, divided between field systems and watercourse alike, its interior overgrown on rough grazing land along a gentle east-facing slope.

Ringforts, known in Irish as raths when formed from earthen banks rather than stone, were the most common type of rural settlement in early medieval Ireland, typically enclosing a farmstead and its associated structures. At Cappanagoul the defensive arrangement is more complex than a simple single bank. Moving around the perimeter, two earthen banks with an intervening fosse, that is a ditch dug between them, protect the north-eastern to east-south-eastern arc. A single earthen bank continues from there towards the south-south-east, giving way to a scarp with an external fosse from south-south-east to south-west, and then to a slight rise with an external depression carrying the circuit towards the west-north-west. Beyond the stream to the north-north-west, a deep fosse completes the picture. This variety in construction across a single perimeter suggests either phased building over time or a deliberate response to the local terrain, with the builder reinforcing the approach from different directions in different ways.