What makes it quietly compelling is the unevenness of its bank: at its tallest, on the northern arc, it rises to about 1.8 metres on the interior face, then gradually diminishes as it curves southward, giving the enclosure a lopsided profile that becomes more legible the longer you look at it.

This is a rath, the earthen variety of ringfort, a class of monument that represents one of the most common surviving traces of early medieval life in Ireland, dating broadly from around the fifth to the twelfth centuries. Raths were typically built as enclosed farmsteads, the bank and its accompanying external ditch serving as a boundary marker and a means of keeping livestock in or predators out, rather than as a military fortification in any serious sense. The place name Barr An tSeanchnoic translates roughly from Irish as the top or summit of the old hill, which fits the modest elevated position the site occupies. The gradual tapering of the bank from north to south may reflect the natural lie of the slope, with more material needed on the uphill side to create an even interior floor, or it may simply reflect centuries of differential erosion and agricultural disturbance across the softer, lower ground.