Though the site now lies beneath meadow grass, making detailed examination difficult, historical records and archaeological surveys have pieced together a picture of this once substantial defensive enclosure.

The bawn appears to have been a rectangular earthwork that surrounded Erry Castle, measuring approximately 35 metres east to west and 40 metres north to south. When first depicted on the 1838 Ordnance Survey map, it was shown as a complete rectangular enclosure around the castle ruins. By the time of the 1908 revised edition, only a short section along the southern side remained visible enough to map. A 1942 survey provides the most detailed description of what survived; the enclosure wall had been reduced to an earthen bank varying in height from 1.5 metres on the south side to just 0.6 metres on the west and north, whilst the eastern section was nearly level with the surrounding ground. The surveyor also noted traces of a defensive fosse, or ditch, and stone wall foundations within the enclosure, including what appeared to be a house structure adjoining the southern rampart.

A later archaeological survey in 1977 confirmed these findings, describing a poorly preserved rectangular enclosure outlined by a broken embankment on the south with an external fosse, and a badly degraded eastern embankment. Today, these subtle earthworks represent the ghostly outline of what would have been a formidable defensive structure; a bawn that once protected the castle’s inhabitants, their livestock, and valuable goods from raiders in an era when such attacks were a constant threat to isolated strongholds across the Irish countryside.