Ringforts, known in Irish as raths when formed from earthen banks and ditches, were the most common settlement type in early medieval Ireland, and tens of thousands of them survive in various states of preservation across the country. They functioned primarily as enclosed farmsteads, the raised banks offering a degree of protection for a family and their livestock rather than serving any serious military purpose. That so many remain visible at all is partly because later generations regarded them with a mixture of superstition and respect, often leaving them untouched in the belief that disturbing a rath invited misfortune.

The townland name Lisduff offers its own small clue. In Irish, lios dubh translates roughly as the black fort or dark enclosure, a name that may once have described the specific appearance of this site, perhaps darkened by vegetation or shadow, or simply distinguished it from a nearby lios of a different character. Townland names in Mayo frequently preserve this kind of fossilised description, recording in compressed form what early inhabitants saw when they looked at the land around them. The rath at Lisduff belongs to a county that contains a considerable number of such monuments, many of them on agricultural ground that has been farmed continuously since the early medieval period.