Drainage spoil dumped from the nearby Inny River has buried the southern portion of a rath that once stood as a complete circular earthwork on the low, marshy ground of Ratharney, and what survives above ground now amounts to little more than a gentle swell in the landscape. A rath, for those unfamiliar with the term, is a roughly circular earthen enclosure, typically of early medieval Irish date, defined by banks and ditches and most likely used as a farmstead or defensible homestead. That so many survive across Ireland at all is remarkable; that this one endures in any legible form, given its setting, is quietly surprising.

The ordnance surveyors who mapped this part of County Longford in 1837 recorded it plainly on their six-inch map with the word "Fort", which was a common enough label for such features at the time. By 1987, when the site was examined more closely, the picture had grown considerably more complicated. The raised circular area measures some 33 metres in diameter. A wide, low earthen bank survives from the north around to the east, set upon a scarp that rises to a maximum height of just 0.25 metres. At the base of that scarp lies an infilled fosse, the ditch that would originally have reinforced the enclosure's boundary, now largely filled in and measuring about 1.6 metres wide. A levelled outer bank, up to 4.8 metres wide and 0.35 metres high, is traceable from the north around through the east to the south-east. No original entrance can be identified. Adjoining the main enclosure on its western side is a smaller secondary enclosure, possibly an annexe to the rath, a feature sometimes associated with keeping livestock or providing additional protected space.