It is easy to miss: a low rim of earth and stone, roughly 6.5 metres across, rising no more than a few centimetres above the interior ground level and perhaps 45 centimetres on its outer face. Yet that modest ring is the ghost of a hut, the kind of simple dwelling that would once have sat within the enclosure of a rath for shelter and security.

A rath, sometimes called a ringfort, is an enclosed settlement typical of early medieval Ireland, usually formed by one or more circular earthen banks. The Ballyhiernaun example is recorded as MA039-057, and the hut site sits slightly east of centre within it. What makes the arrangement here particularly interesting is that the circular hut footprint, with its rim measuring between 1.2 and 1.7 metres wide, occupies the north-west quadrant of a low square platform. That platform measures 13.5 metres on each side and stands just 0.25 metres above the surrounding ground. The combination of a square raised platform and a circular hut within a rath is a quietly unusual configuration, suggesting a layered use of the space that is not always seen at comparable sites.