At Carrigoon in north County Cork, a circular earthwork roughly twenty-seven metres across sits on a gentle south-facing slope, its saucer-shaped interior defined more by subtle contour than dramatic earthen bank. Positioned just above a steep drop to the River Blackwater some thirty metres beyond the site, the rath, as this type of ringfort is often called, would have commanded a useful natural boundary on at least one side.

Ringforts are enclosures, typically circular, built throughout Ireland during the early medieval period, roughly the fifth to twelfth centuries, and used as defended farmsteads by families of varying social rank. Most were defined by earthen banks and ditches; at Carrigoon, what survives is more modest, a low scarp with shallow external depressions to the east-south-east and north-west. Local knowledge adds an interesting detail: when the field has been ploughed in the past, the circular outline of the feature becomes clearly visible as a crop or soil mark, the buried archaeology briefly legible from above ground level. Within the interior there is also a possible souterrain, an underground passage or chamber cut into the earth, typically used in early medieval Ireland for storage or concealment. These features are frequently associated with ringforts and, where they survive intact, can preserve organic material and artefacts in remarkable condition.