This roughly square enclosure, measuring approximately 65 metres north to south and 60 metres east to west, likely once protected Courtstown Castle, though the castle itself has long since vanished. Historical maps from the Down Survey of 1655-6, including both the barony map of Cranagh and the parish map of Tullohan, clearly depict a castle with its square bawn at this location, providing documentary evidence for what archaeology reveals on the ground today.

The defensive earthworks remain remarkably substantial despite centuries of weathering. Along the northern and eastern sides, a formidable earth and stone bank rises 2.1 metres on the interior side and 1.7 metres externally, with a width of 7.6 metres. Beyond this bank lies a waterlogged fosse, or defensive ditch, measuring 2.5 metres wide. The western side preserves a shorter section of internal bank, standing between 0.7 and 1 metre high with a width of 3.8 metres. A causewayed entrance, 2 metres wide, provides access from the north, whilst near the northwestern corner, cattle have broken through creating an additional opening.

Today, the site offers limited views except towards the northwest, north, and northeast, where the landscape opens up. The interior remains waterlogged and marshy, much as it likely was when the bawn served its defensive purpose. Heavy vegetation has claimed the banks, with beech, hawthorn, holly, and ivy creating a thick covering that both preserves and conceals these historic earthworks. The wet conditions that may have aided the site’s defence centuries ago now make exploration challenging, yet they’ve also helped preserve this rare example of a bawn without its associated castle structure.