A togher is a type of ancient roadway built from timber planks or brushwood laid across boggy or waterlogged ground, effectively a causeway engineered to allow passage through terrain that would otherwise be impassable. These structures are among the quieter achievements of early Irish life, practical solutions to a landscape that was, for much of prehistory and the early medieval period, far wetter and more heavily waterlogged than it is today.

The Westmeath midlands sit atop a landscape shaped by glacial activity, scattered with bogs, lakes, and poorly drained soils that made overland movement genuinely difficult for centuries. Toghers were sometimes built to connect settlements, to reach resources on the far side of a bog, or to mark routes of local or regional significance. Some have been dated through dendrochronology, the analysis of tree rings in the preserved timbers, to specific centuries, occasionally to specific decades. The Coolnagun example, however, remains a thin entry in the wider record, noted by Caimin O'Brien in November 2016 but without the supporting documentation that might tell us more about its age, construction, or purpose.