These are toghers, a term from the Irish tóchar, referring to causeways or trackways built across bogland using timber and brushwood. Twenty-nine of them, including some possible examples, were identified during field survey, representing a remarkable concentration of early engineering in a single stretch of wetland.

A survey carried out by Gowen in 1999 recorded the construction methods in some detail. Fifteen of the toghers were built from brushwood alone, while the remainder combined brushwood with roundwood, giving them a more robust form. Three showed evidence of pegs or stakes, suggesting the builders took care to anchor the material against the soft, shifting ground. Wood species were identified in thirteen of the toghers and included alder, ash, birch, elm, hazel, holly, and mountain ash, with ash and hazel appearing most frequently. Hazel in particular was a common choice for woven or bundled trackway construction across Ireland, being flexible, relatively straight, and widely available in wet woodland margins. Radiocarbon dating of one togher placed its construction somewhere between AD 1024 and 1162, placing it firmly in the early medieval period, a time when bogs were actively managed and crossed rather than simply avoided. Whether the others share that date or span a wider range of periods remains, for most of them, unknown.