A rath is an early medieval ringfort, typically a raised circular enclosure defined by one or more earthen banks and ditches, used as a farmstead or settlement by a family of some local standing. This one at Carrownaculla measures about 36.5 metres north to south and 36 metres east to west, making it a fairly typical example of the form, though the survival of original stonework on its eastern arc gives it a certain material specificity.

The bank itself tells a story of uneven survival. On the eastern half, fragments of drystone facing remain on both the inner and outer faces of the bank, the exterior stone rising to around a metre before it gives way to tumbled rubble. The western half has lost almost all its facing, retaining only a low internal lip and a pronounced outward slope. Outside the bank runs a fosse, essentially a defensive ditch, which is sharply defined at the north-east and south-west but fades toward the west and disappears entirely at the north, where a modern field fence cuts across it. The original entrance was on the east-south-east side, a gap of about 1.8 metres wide with a causeway bridging the fosse, which is an arrangement seen at many Irish raths and likely reflects both practical access and the social significance of a formal threshold. A secondary break on the south-west, roughly a metre wide and clearly eroded rather than designed, is presumably a later breach. The interior is level and grassy, with blackthorn creeping in from the north-west quadrant and hawthorn, hazel, and sycamore thickening around the outer bank. The ground falls away to the east toward bog, and a stream lies 270 metres to the north, a configuration that suggests whoever chose this spot was mindful of drainage and water access in equal measure. Two further early medieval enclosures, a second rath and a possible cashel (a stone-built equivalent of a rath), sit about 200 metres to the south and south-east and are visible from this rise, hinting that the area once supported a small cluster of related farmsteads rather than a single isolated household.