This is a rath, the most common type of early medieval settlement monument in Ireland, typically consisting of a raised circular or oval area enclosed by one or more banks of earth with corresponding ditches. What distinguishes this one, modestly enough, is the relative completeness of its double defences and the clarity with which the landscape still holds its shape.

The earthwork measures roughly 31 metres on its north-south axis and is defined by two banks with an intervening fosse, the fosse being the flat-bottomed or V-shaped ditch dug to supply the material for the banks themselves. The inner bank survives from the west around to the north-north-west, while elsewhere the enclosure is defined by a scarp, a steep natural or cut slope that serves the same containing function. The outer bank and fosse remain visible from the south-east, curving south and continuing round to the north-north-west. The northern interior has been disturbed by quarrying at some point, a not uncommon fate for earthworks that were conveniently elevated and therefore useful as sources of loose stone or gravel. A separate enclosure lies approximately 100 metres to the south-south-west, suggesting this part of Slievedarragh was once a more densely organised landscape than it appears today.