Set in an expanse of lowlying, rush-grown pasture, this rectangular enclosure measures approximately 70 metres from north-northwest to south-southeast and 40 metres from east-northeast to west-southwest. The site occupies a slight elevation that rises from the surrounding damp ground, with the ruined castle positioned at its southeast corner.

The western side of this possible bawn presents the most impressive features, with a well-defined scarp standing 0.8 metres high and an external fosse, or defensive ditch, that measures 6.5 metres wide at the top and narrows to 3.6 metres at its base. A subtle rise along the outer edge of this fosse might represent the remains of a levelled bank. While the northern side also displays a clear scarp, the eastern boundary remains low and poorly defined. Halfway along the western edge, archaeologists have noted a curious rectangular rise measuring 11 by 5 metres, though its purpose remains unclear.

First properly documented by Knox in 1913-14, who suggested it might be the remains of a bailey or bawn associated with the castle, the site has changed little in the intervening century. Interestingly, this enclosure doesn't appear on the 1838 Ordnance Survey map, though by the 1920 edition, cartographers had marked the southwest angle and western side with hachuring. Knox also recorded an extensive system of linear banks and ditches extending to the west and south-southwest of the main enclosure, hinting at a more complex defensive landscape than what meets the eye today.