Toghers, as they are known in Irish archaeology, are trackways built from timber laid across boggy or waterlogged ground, effectively floating paths that allowed people and animals to cross terrain that would otherwise have been impassable. What makes the Killoran examples quietly remarkable is the sheer number of them concentrated in one area, and what their construction reveals about the people who built them.

A field survey carried out in 1999 identified twenty-nine toghers, including some possible examples, within the townland. The simplest were made entirely from brushwood, the cut stems and branches of shrubs and small trees pressed into the soft ground. Others combined brushwood with roundwood, the more substantial poles or split timber that gave a firmer surface underfoot. Three of the toghers showed evidence of pegs or stakes, suggesting a more deliberate effort to pin the structure in place and prevent it shifting in the bog. Wood species were identified in thirteen of the toghers, a list that reads almost like a catalogue of the early medieval Irish woodland: alder, ash, birch, elm, hazel, holly, and mountain ash, with ash and hazel used most frequently. One togher was radiocarbon dated to between AD 1024 and 1162, placing it firmly in the early medieval period, though the others remain undated and could span a much wider range of time. The choice of materials was almost certainly practical rather than arbitrary; hazel in particular was widely coppiced and produced straight, workable rods that were well suited to this kind of construction.

Derryville Bog is a raised bog, the kind of deep, acidic peatland that forms over centuries in poorly drained lowland areas and that has, over those same centuries, preserved organic materials that would have rotted away almost anywhere else. It is this preserving quality that has kept the Killoran toghers intact long enough to be found and studied, and that makes the bog itself as much a part of the story as the roads it contains.