To a casual eye it might read as nothing more than a slight swelling in the field, but the geometry is deliberate: a roughly circular enclosure around twenty-three and a half metres across, defined by an earthen bank that is considerably wider than it is tall, with faint traces of a fosse, or external ditch, still detectable along the eastern and southern sides.

This is a rath, the most common type of early medieval settlement monument in Ireland. Raths were typically built between roughly the sixth and twelfth centuries as enclosed farmsteads, the bank and ditch combination providing a degree of security for livestock and family alike. Thousands survive across the country in varying states of preservation, though many have been lost to agriculture over the centuries. The example at Bayswell is modest in scale and worn low by time and grazing, its bank measuring somewhere between eighty centimetres and just over a metre in external height, and the fosse reduced to slight traces rather than any pronounced channel. The choice of its position on the ridge end is characteristic of the type; even a gentle natural elevation offers improved drainage, a degree of outlook, and a certain defensible logic.