This site forms part of a larger complex of earthworks that includes a moated site and Island House, a fortified dwelling that speaks to centuries of defensive architecture in the area. Whilst nothing remains visible at ground level today, the story of this possible castle comes to us through the meticulous work of early 20th century antiquarian H.T. Knox.

In the early 1900s, Knox documented something remarkable here. He discovered a mound adjoining the south side of the moated site that, when excavated, revealed stone foundations of a rectangular building measuring approximately 16 metres by 9 metres. Knox believed these remains represented a stone castle, and the evidence he uncovered was compelling; large, carefully cut quoin stones suggested construction dating to the late thirteenth or fourteenth century, a period when Anglo-Norman influence was spreading throughout Ireland. The structure had been protected by a strong wall that formed a small bawn, or fortified enclosure, on two sides.

Today, this potential castle exists only in Knox’s detailed records and plans, where it appears marked simply as ‘I’. The site serves as a reminder of how much of Ireland’s medieval heritage lies hidden beneath the landscape, waiting to tell its stories. The broader complex of earthworks around Island Lake hints at a significant settlement that once controlled this area, with its combination of moated defences and stone fortifications typical of the Anglo-Norman approach to securing territory in medieval Ireland.