These are toghers, a word from the Irish tóchar, referring to causeways or trackways laid across boggy ground to make it passable. The bog, by sealing out oxygen, has preserved what would otherwise have rotted away centuries ago, leaving behind the evidence of journeys made across an inhospitable landscape long before any mapped road existed.

A field survey carried out in 1999 identified twenty-nine toghers, including possible toghers, within Killoran townland in Derryville Bog. The majority were built from brushwood alone, while others combined brushwood with roundwood in varying proportions. Three showed traces of pegs or stakes, suggesting that at least some builders made an effort to anchor their work against the soft and shifting ground. Radiocarbon dating of a sample from one togher returned a date range of AD 1024 to 1162, placing it firmly in the early medieval period, a time when the Irish countryside was organised around monastic settlements, territorial kingdoms, and the constant movement of cattle and people across difficult terrain. Wood species analysis added further texture to the picture: thirteen of the toghers contained identifiable timber, with ash and hazel the most common, alongside alder, birch, elm, holly, and mountain ash. The choice of species was almost certainly practical rather than incidental, with ash and hazel being both abundant and well suited to the task of bearing weight across soft ground.