This three-storey tower house features a pointed vault over its ground floor and a door with a pointed arch in its south wall. The first floor contains a window with splayed and lintelled details, alongside a square-headed light, whilst the central window openings pierce the south wall. Though part of the parapet still stands, the crenellations that once crowned the structure have long since disappeared.

The castle's origins remain somewhat mysterious, possibly belonging to either the O'Cowhig family or the MacCarthy Reagh clan. Grass-covered foundations of an oblong building, approximately 45 feet long, can still be seen adjoining the tower to the southwest; these were first documented by Westropp in 1914. The same historical records tell us that Crown forces captured the castle in 1602, when it could only be reached by "a little drawbridge of wood", suggesting its strategic defensive position was well utilised by its medieval occupants.

Adding another layer of intrigue to this site, archaeologist Casey proposed in 2003 that the island might have hosted an even earlier fortification, possibly a promontory fort. He observed a curving boundary and undulations on the nearby headland that could represent ancient earthworks, though the evidence remains too fragmentary to draw definitive conclusions. These tantalising hints suggest that this dramatic rocky outcrop has been valued as a defensive position for far longer than the standing medieval ruins might indicate.