The enclosure measures 34 metres across in both directions, a near-perfect circle that speaks to deliberate planning rather than natural accident. What lifts it slightly above the ordinary is the scale of its defences: an earthen bank rising to 3.1 metres, faced on its inner side with stone, and an external fosse, or ditch, cut to a depth of 1.8 metres. Together, these features would have presented a formidable barrier, far more so than the grassed-over mound suggests today.

This is a rath, the Irish term for a ringfort, the most common type of enclosed settlement in early medieval Ireland, typically dating to somewhere between the sixth and tenth centuries. They were generally the farmsteads of prosperous families, the bank and ditch serving less as military fortifications and more as a statement of status and a means of enclosing livestock. The entrance at Ratooragh faces roughly east-southeast and measures four metres wide, a width comfortably sufficient for animals as well as people. Particularly interesting is the evidence of cultivation ridges crossing the interior on an east-west axis. These lazybeds, as similar ridges are often called elsewhere, suggest that the enclosed space was given over to tillage at some point, either during the site's original occupation or in a later period when the earthwork's original purpose had been forgotten and the sheltered ground inside simply put to agricultural use.