It is a togher, a form of ancient trackway constructed from timber and brushwood to carry people and animals across the waterlogged midland bogs that would otherwise have been impassable. This particular example is modest in scale, thirty metres long and just under three metres wide, but its modest dimensions should not obscure the precision that went into its making.

The togher was built in two distinct layers. The substructure, the foundation laid directly into the wet ground, consists of ash brushwood, chosen for its flexibility and strength. Above it, the builders arranged a superstructure of interwoven ash, hazel and birch branches, each branch between three and five and a half centimetres in diameter, creating a firm if springy surface underfoot. What makes the Derrynagran togher particularly telling is that toolmarks were visible on the timber. Those marks confirm that the wood was not simply gathered from the ground but actively cut and shaped, suggesting a deliberate construction effort rather than a casual improvisation. The trackway runs on a broadly east-northeast to west-southwest orientation, a line that would have connected two points across the bog with some intention behind its direction. Research into the site was carried out by the Irish Archaeological Wetland Unit, based at University College Dublin, a body that systematically recorded Ireland's remarkable concentration of bog roads before many were disturbed by turf-cutting or drainage.