A rath is a ringfort, one of the most common monument types in the Irish countryside, typically consisting of a roughly circular earthen bank enclosing a domestic space used during the early medieval period, roughly between the fifth and twelfth centuries. There are estimated to be around forty thousand such sites across Ireland, yet each one occupies a specific patch of ground that once mattered to a particular family or community, and the one at Cloonflyn is no exception.

Ringforts of this kind were the farmsteads of early medieval Ireland, built to enclose a household and its activities rather than to defend against serious military attack. The bank and ditch served as much to keep livestock in and wolves out as to deter human interference. In the centuries that followed their abandonment, many were absorbed into field systems, ploughed away, or simply left to grass over, becoming the low circular swellings that catch the eye in oblique evening light. The Cloonflyn example is recorded as a monument of this type in Mayo, a county where the density of such sites reflects the long continuity of rural settlement across the west of Ireland.

Beyond its classification and location, the documentary record for this particular site is thin. What can be said is that the townland name Cloonflyn, from the Irish meaning something close to a meadow or plain, suggests the kind of open, workable ground that early farmers would have sought out when choosing where to build and settle.