The one at Ballyroe in County Kerry is a case in point: a rath, which is the Irish term for a roughly circular earthwork enclosure typically built during the early medieval period, between around 500 and 1000 AD. These structures served as farmsteads for families of middling social rank, their raised earthen banks defining a boundary between the domestic world inside and the agricultural land beyond. The vast majority were never given names in historical records, never saw a notable siege or a documented royal visit, and survive today simply as low humps and curves in otherwise ordinary fields.