When archaeologist Celie O’Rahilly conducted excavations at the site in 1991, even careful investigation failed to uncover any physical remnants of this rectangular fortification that once protected the castle grounds. The only evidence we have of its appearance comes from a contemporary drawing of the 1600 siege of Glin Castle, which provides valuable insight into the bawn’s original design and layout.

According to this historical illustration, the bawn formed a rectangular enclosure with the main tower positioned at its southwest corner. The defensive walls featured crenellations along their length, typical of military architecture of the period, whilst the main entrance gateway stood centrally along the northern wall. The western side housed a substantial hall built against the interior wall, likely serving as accommodation or gathering space for the castle’s defenders and residents.

The fortification was further strengthened by two additional corner towers at the northeast and southeast angles, creating a formidable defensive perimeter around the castle proper. This configuration would have provided overlapping fields of fire and eliminated blind spots, making any assault on the castle considerably more difficult. Though the physical structure has been lost to time, the detailed drawing from the 1600 siege ensures that the memory of this significant piece of Irish military architecture remains preserved for historical study.