This rectangular grass-covered enclosure stretches 61.3 metres from east to west and 42 metres from north to south. Earthen banks, ranging from 2.2 to 3.2 metres wide, define the northern and eastern boundaries, whilst a scarp up to a metre high marks the remaining edges. The site is surrounded by defensive fosses, or ditches, which measure between 4.4 and 6 metres across at the top, narrowing to 2.1 to 3.7 metres at the base, though curiously no visible entrance remains.

What makes this site particularly intriguing is what lies beneath. In 2008, the Discovery Programme conducted magnetic gradiometry surveys that unveiled an earlier enclosure or rath hidden within the northwest corner of the moated site. This discovery suggests the location held significance long before the medieval period, with successive generations choosing to build upon this same hillside spot. Another possible rath lies approximately 190 metres to the west, hinting at a broader archaeological landscape.

The moated site represents a type of medieval settlement typically associated with Anglo-Norman colonisation in Ireland during the 13th and 14th centuries. These rectangular enclosures, defended by banks and water-filled ditches, often housed timber buildings and served as fortified farmsteads for colonising families. The site at Cloonybeirne, with its earlier rath beneath, beautifully demonstrates the continuity of settlement in the Irish landscape, where medieval newcomers built atop ancient Irish foundations.