Raths, or ringforts, are among the most common archaeological monument types in Ireland, with tens of thousands recorded across the island, yet each one represents a farmstead enclosed by a raised bank and ditch, home to a family or small community during the early medieval period. Their very ordinariness is part of what makes them worth noticing: they are not dramatic fortifications but the ordinary infrastructure of a rural society that has long since dissolved into the grass.

The townland name Lack derives from the Irish leac, meaning a flagstone or flat slab, a small linguistic clue that the ground here has its own character. Mayo as a county contains a considerable density of ringforts, many of them tucked into marginal land that was never extensively ploughed, which is part of why so many have survived at all. The earthen banks of a rath could be levelled in a single season of agricultural improvement, and across much of Ireland that fate befell thousands of them during the eighteenth and nineteenth centuries. Those that remain tend to occupy corners of fields, slopes, or areas of poorer soil where clearance simply was not worth the effort.