The site consists of rectangular wall footings that mark the castle’s original footprint, surrounded by a distinctive D-shaped enclosure measuring approximately 35 metres north to south and 50 metres east to west. This enclosure is defined by an earthen bank, though centuries of weathering have reduced it to a mere scarp along the western and southern sides, whilst a substantial outer fosse; a defensive ditch some 3.6 metres wide and up to 2 metres deep on the interior side; runs around the perimeter, though it has been filled in from the northern to eastern sections.

The straight western edge of the D-shaped enclosure features a causewayed entrance, 5 metres wide, at the southwestern corner that would have provided access to the castle’s courtyard. Archaeological evidence suggests this may not be the full extent of medieval activity at the site; low, irregular earthworks to the southwest of the castle could represent the remnants of an associated settlement, though these features might equally be the result of later agricultural land reclamation efforts.

The relationship between the castle and its enclosure presents an intriguing puzzle for historians. One possibility is that the D-shaped earthwork predates the castle entirely, perhaps serving as an earlier fortification that was later repurposed as a bailey when the castle was constructed during the medieval period. Alternatively, the enclosure and castle may be contemporary, with the earthwork serving as the original bawn or defended courtyard that protected Faheeran Castle and its inhabitants from the uncertainties of medieval Irish life.