A rath, as these enclosures are known, was typically a circular or oval earthwork enclosing a farmstead, built and occupied during the early medieval period, roughly between the fifth and twelfth centuries. This one at Brackloon measures approximately 42.8 metres on its longer axis and 38 metres across, which places it comfortably within the normal domestic scale. What makes it quietly interesting is not grandeur but survival, and the way the landscape has slowly absorbed it without quite erasing it.

The earthwork has been partly levelled over the years, whether by farming activity or simple erosion it is difficult to say, but the underlying structure can still be read from the ground. A low bank or scarp, around three metres wide and only about 20 centimetres high in places, marks the circuit of the enclosure and remains most legible on the north-east, east, and southern sides. Beyond this, on the western half, traces of a fosse survive, a fosse being the ditch dug to provide material for the bank and to add a degree of defence or demarcation. On the south and south-west this ditch is still clearly defined at 2.5 metres wide, though it fades to a shallow depression as it curves north. An external bank, between 2.5 and 3 metres wide and standing internally to about 0.8 metres, can be traced from the south-south-west around to the west, where it merges with a broad slump in the ground level that is itself some 5.5 to 6 metres wide and 2.5 metres in height. A slight terrace on the north-east and east probably preserves the original line of the fosse and outer bank on that side. A farm shed now sits against the south-east edge of the enclosure, directly over the fosse and outer bank at that point.

Inside, the central and eastern sectors are relatively level ground, but there is a noticeable drop towards the south and west. A field wall running on a north-west to south-east axis cuts across the interior to the north-east of centre, a later addition that speaks to the site's long afterlife as ordinary farmland. The farmstead immediately to the east and south-east has grown up in close proximity to the rath, and the two have existed in each other's company long enough that the boundary between archaeological feature and working landscape has become genuinely ambiguous in places.