These are pre-bog walls, meaning they were built before the blanket bog grew up and, in places, consumed them, which makes them considerably older than the landscape now surrounding them. That alone gives the site an unsettling quality: the fields these walls once divided were in use at a time when this mountainous terrain looked and functioned quite differently, before the slow accumulation of peat transformed it into the boggy upland it is today.

The complex covers an area of roughly 600 metres north to south and 380 metres east to west. The walls vary considerably in form and scale. At the southern end, one wall runs east to west for about 15 metres, built from large boulder-like slabs, most of them set upright. Further north, a long curvilinear stretch of similar construction almost encircles a low knoll, and a third wall curves in a broad semicircle for 140 metres to its north-east. Two further adjoining walls climb the mountain slope for several hundred metres, these ones composed of flat slabs, small boulders, and occasional uprights. The whole arrangement suggests organised land management across a substantial area, with enclosures of a type known as fionnán, a term referring to small, often irregular enclosures associated with early agriculture in upland settings. A modern field boundary cuts across part of the complex, a reminder that the land has continued to be used, in different ways, long after the bog buried the original intent of these walls.