This is a togher, an ancient form of trackway built to allow people and animals to cross the soft, treacherous ground of Ireland's midland bogs, and the example at Derrindiff offers a quietly precise record of the craft involved.

The structure runs east to west and measures 4.4 metres in width, which is broad enough to suggest it served as a genuine thoroughfare rather than a narrow footpath. It was built using a combination of transverse and longitudinal roundwood, the timbers laid both across and along the direction of travel to create a stable, interlocking surface. The wood came from alder and hazel, both common to wet and marginal woodland environments, with the roundwood pieces reaching up to around nine centimetres in diameter. Woven among the larger timbers is a scatter of hazel brushwood, averaging only about two centimetres across, which would have helped fill gaps and distribute weight across the surface. This layering of materials is characteristic of what archaeologists classify as a class 3 togher, a construction type that reflects considered engineering rather than improvised crossing. The shallowness of the deposit, less than twenty centimetres deep, hints at the compressed archaeology of bogland, where centuries can be preserved in a relatively thin band of peat.