Ringforts, or raths, are enclosures typically built during the early medieval period in Ireland, formed by one or more banks of earth thrown up around a central living or farming area. Most contain no internal features visible at the surface. This one is different.

The place-name offers a starting point. Rathoran derives from the Irish Ráth Odhráin, meaning the ringfort of a person named Odhrán, suggesting some degree of individual ownership or association in the early medieval period, when such sites were commonly in use. The rath itself is univallate, meaning it has a single enclosing bank rather than two or three, and that bank is substantial: roughly 7 metres wide at its base, rising to 2.2 metres on its outer face. The interior measures approximately 41 metres north to south and 38 metres east to west, an oval space of considerable size. A stream curves around the northern and western exterior, providing a natural boundary that would have supplemented the earthen bank, while a fieldbank marks the north-eastern and south-western limits. Inside, the three mounds vary considerably in size, from a modest rise of about 1.2 metres by 1 metre in the north-east, to a much larger central mound measuring 4.2 by 4.4 metres. Whether these represent the remains of structures, deliberate deposits, or something else entirely, the record does not say. The notation of a 'cave' on the mid-nineteenth-century map adds a further layer of uncertainty; such a feature might indicate a souterrain, an underground stone-lined passage often associated with ringforts and used for storage or refuge, though no further detail survives to confirm this.