No earthworks break the surface, no visible bank or ditch survives to catch the eye. The only evidence that anything was ever here is a set of hachure marks on an Ordnance Survey map from 1929, indicating a circular enclosure roughly 36 metres in diameter. By the time anyone thought to record it more formally, the ground had long since levelled out.

Ringforts, sometimes called raths, were the most common form of early medieval rural settlement in Ireland, typically consisting of a raised circular area enclosed by one or more earthen banks and ditches. They were used as farmsteads, and thousands survive in varying states of preservation across the country. This one in Tullyduff sits approximately 200 metres south-west of a cashel, which is the stone-built equivalent of a ringfort, suggesting that whoever occupied this landscape in the early medieval period was active across a fairly concentrated area. The cashel survives; the enclosure beside it does not, at least not in any form that a walker crossing the field would recognise. Whether the hachures on the 1929 map were recorded from faint traces that have since disappeared entirely, or from older documentary sources, is not clear. The site is listed as possibly a ringfort, which is a careful way of acknowledging that the circular outline alone is not quite enough to confirm the classification with certainty.