Ráth Muireagáin, in County Mayo, takes its identity from the Irish word ráth, referring to a ringfort, the circular enclosures defined by earthen banks and ditches that were among the most common forms of settlement in early medieval Ireland. Tens of thousands once existed across the island, yet each carried its own name, its own local memory, and often its own patron. This one carries the personal name Muireagán, a figure now otherwise unrecorded, whose connection to this particular patch of Mayo ground is lost to time.

Ringforts of this kind were typically built and occupied between roughly the fifth and twelfth centuries, serving as farmsteads for families of middling or higher social rank. The enclosing bank offered a degree of protection for livestock as much as for people, and the interior would have held a timber or wattle house, outbuildings, and the ordinary apparatus of rural life. That so many survive in some form across Ireland is partly a matter of folklore, since a widespread belief that ringforts were the dwellings of the sídhe, the supernatural beings of Irish tradition, discouraged their destruction even long after their original purpose was forgotten. Whether Ráth Muireagáin owes its survival to that same superstition is impossible to say, but the possibility is not a small one.