It begins at the headwaters of a small stream west of Lismore, on the northern bank of the Blackwater, and terminates far to the south-east at the headwaters of the Monavugga River, which flows into the Blackwater at Cappoquin. In between, it shifts character as the terrain demands, moving from lowland field bank to upland earthen mound to dry-stone wall, adapting rather than asserting.

The structure changes its construction technique depending on where it sits in the landscape. In the lower-lying western sections, it presents as a stone-faced earthen bank, around three metres wide and a metre and a half high, with a sod core in the higher ground. On steeper slopes, it simplifies to a stone-built wall, one to two metres across. A linear earthwork of this kind, sometimes called a boundary ditch or territorial dyke, was typically used to delineate the edges of a kingdom, estate, or ecclesiastical holding, though no specific historical origin has been attributed to this one. It passes through a string of named townlands including Bohernagore West, Graigue, Gortacullin, Kildanoge, Knockballiniry, and Curragh, following the modern county boundary eastward for roughly eight kilometres before turning south. The fact that it aligns so closely with the present county boundary suggests it may have formalised or preserved a much older division of territory, one that later cartographers and administrators found it convenient to adopt rather than redraw.