These structures, known in Irish as raths, were the farmsteads of early medieval Ireland, typically dating from roughly the fifth to the twelfth centuries. A bank of earth, sometimes reinforced with stone, enclosed a family's dwelling and outbuildings, offering a degree of security and a clear statement of territorial claim. Tens of thousands of them were built across the island, and a remarkable number survive, worn down by weather and farming but still legible as circles from the air or from a nearby rise in the ground.

Lissaniska is a quiet townland name, and the rath it holds is one of countless such sites that punctuate the Mayo countryside without fanfare. The county has a dense concentration of ringforts, a reflection of the settled agricultural communities that worked this landscape during the early medieval period. Many raths in the west of Ireland were later absorbed into local folklore as the dwelling places of the sídhe, the supernatural beings of Irish tradition, which gave them a kind of informal protection: farmers were often reluctant to level a fairy fort even when it interrupted a field boundary. Whether that reputation has helped preserve the Lissaniska example is not known, but the instinct to leave such sites alone has saved many that might otherwise have been ploughed out.