At a mountain gap in the Monavullagh Mountains called Bearna na Madra, a low drystone wall traces out a near-rectangle in the grass, sitting quietly between two shoulders of higher ground. It is not a particularly dramatic structure; the wall rises only between 0.2 and 1 metre, and its width varies from one to two metres. But its position, its shape, and its proximity to a standing stone roughly ten metres to the north give it a quality that goes beyond the merely functional. Something deliberate happened here.

The enclosure measures approximately 21.5 metres north to south and 17.5 metres east to west, with two entrances on its western side, each just over two metres wide. Drystone construction, which relies on carefully fitted stones rather than mortar, is one of the oldest building techniques in Ireland, and structures of this kind are notoriously difficult to date without excavation. What can be said is that the enclosure was already old enough to be recorded on the Ordnance Survey six-inch maps of both 1840 and 1928, appearing in both editions as a subrectangular feature. Its relationship to the nearby standing stone, a type of monument most commonly associated with prehistoric activity, raises the possibility that this corner of the Monavullaghs was a place of some significance long before anyone thought to write it down. The gap name, Bearna na Madra, meaning the gap of the dog in Irish, adds a layer of local colour without explaining anything.