This is a rath, the Irish term for an earthen ringfort, and the raised platform at its centre measures just over 25 metres across internally. It is enclosed by a substantial earthen bank, and beyond that a wide, shallow fosse, the defensive ditch that would once have reinforced the sense of enclosure. These were the farmsteads of early medieval Ireland, typically occupied between roughly the fifth and twelfth centuries, built by farming families who enclosed their homes, animals, and domestic lives within a ring of earth and sometimes timber.

What makes the Devally example worth a closer look is the detail of its surviving earthworks. A modern counterscarp bank, the low outer lip of the fosse, still traces two distinct arcs around the site, running from the south-west around to the west-north-west, and separately from the north around to the north-north-east. This kind of additional outer banking sometimes developed through later agricultural use of the site rather than original construction, which is why distinguishing a modern counterscarp from original defensive features matters to anyone trying to read the landscape accurately. The original entrance to the enclosure has not been identified, which is common enough; entrances were often narrow and their earthen traces are the first things to be lost to centuries of use and erosion.