But the shape of the land tells a more specific story. This is the remnant of a rath, the Irish term for a ringfort, the kind of circular enclosed farmstead that was built in great numbers across Ireland during the early medieval period, roughly between the fifth and twelfth centuries. Most were domestic rather than military in character, enclosing a family's dwelling and outbuildings within a bank and, often, a ditch.

The Brackloon example was recorded on the Ordnance Survey's six-inch map of 1838, where it appeared as a roughly circular enclosure somewhere between 35 and 40 metres in diameter. It was not carried forward onto later map editions, which suggests the monument was already being absorbed into the working landscape. Today the remains form a roughly D-shaped platform, measuring about 28 metres on its longer northwest to southeast axis. The curved northwestern side retains an earthen bank around 1.5 metres wide, standing roughly 0.55 metres above the interior and 0.8 metres above the exterior ground level. A dip of two to three metres in width running just outside this bank may represent a fosse, the shallow ditch that typically accompanied a ringfort bank. The straight southwestern side of the D is no longer defined by any original fabric; instead, a field wall and townland boundary now occupy that line, and south of it no trace of the original southern arc of the enclosure can be detected at ground level. A farm track has clipped the northern edge of the site, further reducing what can be read from the surface.