This oval mound rises 5.5 metres high, its steep sides leading to a summit that measures roughly 30 metres north to south and 21 metres east to west. The top isn’t perfectly flat; instead, it slopes gently inward from the rim towards the centre, creating a subtle bowl shape. The entire mound is covered in grass, making it clearly visible against the surrounding pasture.

What makes this site particularly interesting is the rectangular raised area attached to its northern side, measuring 50 metres east to west and 15 metres north to south. This platform, which sits about 2.5 metres above the external ground level, is likely the remains of a bailey; the fortified courtyard that would have accompanied the main defensive structure. A fosse, essentially a defensive ditch about 3 metres wide and half a metre deep, separates this bailey from the main mound. While dense scrub has overtaken the bailey area, the separation between the two features remains clearly defined.

The castle’s location appears to have been carefully chosen for strategic purposes. Built approximately 400 metres east of what’s now Ballygrania Bridge, it would have controlled an important ford across the Arrow or Unshin River. This positioning would have allowed the castle’s occupants to monitor and control river crossings, a crucial advantage in medieval Ireland when rivers served as both transport routes and defensive barriers. The earthwork represents a typical Norman motte and bailey castle design, a type of fortification that appeared across Ireland following the Anglo-Norman invasion in the late 12th century.