The site, recorded in the Civil Survey as having ‘a bawn and one decayed house’, tells a story of gradual collapse across centuries. Local tradition from the early 19th century credits a Bishop O’Boyle with the castle’s construction, though the exact date remains uncertain.

The castle’s decline is remarkably well documented. In 1847, local historian Fagan noted that a round tower once stood at the eastern end, rising about 40 feet alongside two gables that had survived into living memory. The structure, along with its courtyard, originally measured an impressive 150 feet square, with walls built largely without cement. One gable collapsed in 1793, followed by another in 1844, with the tower falling around the same time. Three cannons once defended the island; two were lost to the lake waters during an 18th century transport attempt, whilst the third remained near the castle ruins as late as 1847.

Today, the former island has joined the mainland on its southwest side, leaving only about six metres of the western wall standing; a thick structure measuring two metres wide and three and a half metres high. Despite its precarious condition, fascinating details remain visible, including a mural staircase that rises from south to north, measuring 1.3 metres wide and 1.5 metres high. The southern section, which narrows to about 92 centimetres above the stairs, preserves traces of a simple rectangular window. Grass now covers the lower courses of several walls that extend westward, silent witnesses to what was once a formidable defensive structure.