What looks at first like a slight swelling in the pasture near Banagher is, on closer inspection, the surviving earthwork of a rath, the Irish term for a roughly circular enclosure defined by an earthen bank and ditch, built and inhabited during the early medieval period. Thousands of these survive across Ireland in varying states of preservation, but this particular example has worn down to something almost geological in its modesty, its bank slumped and eroded, stones protruding at odd angles along its western half, the whole structure blending quietly into the surrounding farmland.

The rath measures roughly 17.4 metres north to south and 16.6 metres east to west, making it a relatively modest enclosure. The earthen bank that defines it varies considerably in what it has managed to hold onto: at the south-west it still stands to an external height of 1.4 metres, while at the north-north-east it has been reduced to just 0.6 metres. Farm stock have done further damage over the years, eroding sections of the bank and in doing so accidentally exposing its interior composition, which turns out to be hard-packed stony sandy soil. There is no identifiable entrance gap, and the interior is largely level and featureless, though it rises slightly in the western third. Remnants of later field fences can be seen butting up against the bank at the south and north-east, evidence of the way agricultural boundaries accumulated around and against the older structure across the centuries. A road runs just three metres to the west. Around 200 metres to the south-west, there is a second possible rath, which would make this part of Banagher unusually dense with early medieval activity, if both sites prove to be what they appear.

The setting itself offers some context for why someone once chose this spot. The rath sits at a low elevation but with a clear eastward outlook over Killala Bay, the same bay that would later become famous as the landing point of a French expeditionary force during the 1798 rebellion. To the south and west, the view opens across rolling fields. For whoever enclosed this small circle of ground over a thousand years ago, that combination of coastal visibility and agricultural land would have been precisely the point.