The example at Esker in County Galway is subcircular in plan, measuring roughly 72 metres north to south and 68 metres east to west at the crest of its outermost bank, making it a substantial enclosure by any measure. A rath, to give it its Irish term, was typically an earthen ringfort used as a defended farmstead during the early medieval period, roughly the fifth to twelfth centuries, and the elaboration of multiple banks generally signals higher social status or a site of particular local importance.

What is striking here is the uneven survival of those three concentric circuits. The inner bank and its accompanying fosse, a fosse being simply the ditch dug to throw up the bank material, remain clearly legible from the north-west around through north to south-east, but have been almost completely levelled on the opposite side. The middle bank and middle fosse fare worse still, surviving only in the northern arc. The outer bank and outer fosse, by contrast, can be traced for nearly the full circumference, giving the site an odd quality where the outermost edge reads more clearly in the landscape than the innermost one. Several gaps are visible around the circuit, though none are thought to be original entrances. The interior has not escaped disturbance either; a large pit has been dug into the northern half, the kind of intervention that, over many centuries, could reflect anything from treasure-hunting to agricultural clearance.

The site sits in flat grassland and is partially obscured by tree cover, which affects how much of the earthwork is legible on the ground at any one time. The northern arc, where the inner and middle elements are best preserved, rewards the closest attention.