The one at Hollowpark in County Mayo belongs to this quiet category: a rath, which is the Irish term for a roughly circular earthen enclosure typically dating from the early medieval period, somewhere between the fifth and twelfth centuries. These enclosures functioned primarily as farmsteads, defined by one or more earthen banks and ditches that offered a degree of security for a family and their livestock rather than any serious military fortification.

Beyond its classification and location, the documentary record for this particular site is currently thin. What can be said is that Mayo contains hundreds of such monuments, many of them surviving in varying states of preservation across a landscape that was intensively farmed and settled throughout the early medieval period. The name Hollowpark itself carries a certain topographical suggestion, hinting at a sheltered or low-lying position of the kind that early farmers often favoured when choosing where to establish a homestead, close to water and with natural protection from wind. Whether that reading of the place-name holds up, and what archaeology might lie beneath the surface of this specific enclosure, remains to be properly documented.