This is a bivallate rath, meaning a ringfort enclosed by two concentric banks rather than the more common single ring, and that doubling was once a mark of some status. The earthen wall of the inner enclosure rises to around seventy centimetres on its outer face and sixty centimetres above the interior, modest dimensions that nonetheless would have defined a clear boundary between the household within and the wider world without.

The outer bank has not fared as well as the inner. It survives only along the north-northwest to west arc of the site, where it ranges between roughly one and a half and five metres in width and stands no more than thirty centimetres above the surrounding ground. Between the two banks lies a fosse, a defensive ditch, which is only still legible in those sections where the outer bank remains intact; it measures between about one point eight and two point two metres across. The survival of just one portion of the outer circuit is not unusual for sites like this. Centuries of agriculture, land clearance, and general neglect eat away at earthworks gradually, often leaving one sheltered or less-farmed arc standing while the rest dissolves back into the field. The sub-circular shape of the inner enclosure is characteristic of the rath as a building type, which functioned primarily as a farmstead during the early medieval period in Ireland, roughly the fifth to twelfth centuries. The ditch and banks were as much about enclosing livestock and marking territory as they were about defence. The site at Rathoran was recorded in Caroline Toal's North Kerry Archaeological Survey, published in 1995.