A rath, to give it its Irish designation, is a roughly circular enclosure defined by one or more earthen banks and ditches, built primarily during the early medieval period, between roughly the fifth and twelfth centuries. These were farmsteads rather than fortresses, the homes of farming families who measured their social standing partly in the solidity of the bank around them. The name Doonmaynor itself carries traces of this world: the element "dún" refers in Irish to a fort or enclosed place, suggesting that the site left a deep enough impression on the landscape to anchor the place-name long after its original inhabitants were gone.

The townland setting in Mayo places this site within a province whose early medieval archaeology remains, in many areas, less thoroughly examined than that of Leinster or Munster. Connacht's ringforts tend to occupy ground that reflects the mixed pastoral and arable farming of the period, often positioned with a practical eye for drainage and visibility rather than any purely defensive logic. Without more specific detail available for this particular site, what can be said with confidence is that its survival into the present is itself significant. Many ringforts were levelled during the land clearances and agricultural intensification of the eighteenth and nineteenth centuries, and those that remain often do so because the enclosing bank made the interior awkward to plough, or because local tradition attached enough unease to the site to discourage interference. In parts of Ireland, ringforts are still known as fairy forts, and that association has quietly protected a good number of them.