A rath, or ringfort, is essentially a circular enclosure defined by one or more banks and ditches, built during the early medieval period, roughly between the fifth and twelfth centuries, and used as a farmstead and place of shelter for a family of some local standing. Ireland has tens of thousands of them, yet each one is particular to its ground, its townland, its gradual subsidence back into the earth.

Mullenbeg is a quiet corner of Kilkenny, and the ringfort there belongs to a category of monument that shaped the Irish countryside more thoroughly than almost any other. These enclosures were not military fortifications in any grand sense but working farmsteads, with the raised banks serving to keep livestock in and wolves or rival neighbours out. The internal space would have held a house, outbuildings, and the daily business of an early Christian-era household. Over the centuries, many such sites were ploughed away, built over, or absorbed into field systems, making those that survive, even partially, worth pausing over.