These circular earthwork enclosures, known in Irish as raths, were the farmsteads of early medieval Ireland, typically dating from around the fifth to the twelfth century. A bank of earth, sometimes reinforced with stone, defined the boundary of a family's world, separating the domestic space from the fields and pasture beyond. Tens of thousands of them survive across the country in various states of preservation, yet each one represents a particular household, a particular patch of ground, chosen and shaped by people whose names are almost never recorded.

Listernan is a small townland, and beyond its location in Mayo, the documentary record for this particular site is thin. What can be said is that Mayo's landscape carries an unusually dense concentration of early medieval remains, a reflection of how intensively the province was settled during the period when rath-building was the dominant form of rural organisation in Ireland. The earthen banks of a rath were not defensive in any serious military sense; they marked ownership, kept livestock in, and perhaps lent a degree of social status to the household within. Over centuries, many were levelled by agriculture or simply eroded, which makes those that survive, however modestly, worth noting.