It appears on the old Ordnance Survey 25-inch map as a vague subcircular trace, and on the ground it presents as little more than a grass-covered oval with a spread of stone around part of its perimeter. That modesty is, in a sense, the point. This is a cashel, a type of ringfort defined by a stone wall rather than an earthen bank, and the distinction matters: where a conventional ringfort was typically thrown up from dug soil and sod, a cashel relied on gathered or quarried stone, often in areas where the geology made digging impractical.

The enclosure at Brackary Beg measures roughly 31 metres east to west and 22 metres north to south internally, dimensions that place it in the middling range for this class of monument. The stone spread defining its boundary reaches a maximum width of around 4.2 metres at the southern arc and stands about a metre high on its outer face, though on the interior it has been reduced in many places to a low scarp just a metre tall. The northern and south-western sections retain the most coherent stonework; elsewhere the wall has slumped or been robbed out over the centuries. No original entrance survives in recognisable form, which is not unusual where stone has been reused by later farmers, and a farm track now cuts east to west across the northern interior, a small domestic intrusion that has been quietly rearranging things for some time. Ringforts of this kind were typically built during the early medieval period, roughly the fifth to twelfth centuries, and functioned as enclosed farmsteads for a single family and their livestock, the stone boundary serving as both boundary marker and a deterrent to cattle raiders.