Most enclosures of this type in Ireland are roughly circular, the product of long agricultural and social tradition, but the one at Ballyguilebeg has a distinctly straight western side, giving it a D-shape that sets it apart from the more familiar ring. That geometric irregularity is easy to miss at ground level, but it shapes everything about how the site reads in the landscape.

The enclosure was recorded by Denis Power and uploaded to the Archaeological Survey of Ireland in August 2011, with supporting aerial photography taken in October 2002. According to those records, the earthwork measures 20.4 metres north to south and 32.1 metres east to west, making it a modest but clearly intentional structure. It is defined by an earthen bank, the kind of raised boundary built up from material dug out alongside it, which rises about one metre above the interior ground level and roughly 1.7 metres above the exterior. Outside the bank runs a fosse, the term for the accompanying ditch, here measuring around 0.65 metres deep and 0.8 metres wide. A gap of nearly three metres in the bank on the south-south-west side likely marks the original entrance. A field boundary has been built directly against the south-west corner of the enclosure at some point, suggesting the feature was simply absorbed into later agricultural arrangements rather than deliberately preserved or cleared away.

The site sits in pasture near the crest of a low hill, and the interior ground slopes gently downward toward the north. That slight gradient is one of the details that becomes more legible once you are standing inside, looking across what would have been an enclosed and defined space. There is no public facility or signage here; it is the kind of site that rewards careful map reading and a willingness to look past the obvious. The earthworks are subtle, and without knowing their dimensions in advance, the bank and fosse can read simply as field features. An aerial view, as the 2002 photographs demonstrate, makes the D-shape far more legible than any ground-level inspection.