The castle occupies the western tip of the island, where an oval platform roughly 21 by 18.5 metres has been constructed, rising about 0.7 metres high. This platform is enclosed by a substantial stony bank, standing 1.5 metres on the inside and 1.2 metres on the outside, with a defensive fosse or ditch running along the landward side; 3 metres wide and a metre deep, cutting the castle off from the rest of the island.

The most visible remnants of the castle itself sit on the eastern side of the platform, where a rectangular stone structure once stood, measuring approximately 7.3 by 4.7 metres internally. Though time has reduced much of it to a rubble mound covered in grass, careful observation reveals fragments of its original construction, particularly along the southern wall where external facing stones remain visible, including blocks of dressed limestone that hint at the building’s former sophistication. A later addition, a drystone field boundary wall about 1.25 metres thick and 0.3 metres high, extends from the southern side of these ruins down to the lakeshore, effectively sealing off the western end of the island.

This fortification represents one of several castles built by the O’Gara family, who held considerable power in this region of County Sligo during the medieval period. The strategic position, surrounded by water on three sides with only a narrow approach from the east, would have made it an easily defensible location, whilst the dressed limestone blocks suggest this was more than a simple military outpost; it was likely a residence befitting the status of one of the area’s prominent Gaelic families.