The term earthwork covers a wide range of constructed or modified ground features, from prehistoric enclosures and burial mounds to the defensive banks and ditches of early medieval ringforts, and without more specific detail it is difficult to say precisely what form this one takes or what period it belongs to. That ambiguity is itself part of what makes it worth noting. County Mayo has a dense and varied archaeological record, and earthworks of all kinds are scattered across its fields and hillsides, many of them unexcavated and incompletely understood.