This island, now surrounded by marshy land due to centuries of drainage work, may have originally been a crannóg; an artificial island dwelling typical of early Irish settlements. The castle that crowns it today appears as a roughly square tower built from rubble walls, though heavy overgrowth obscures many of its architectural details and no cut stone remains visible.

Historical records provide a glimpse into the castle’s turbulent past, with documentation from 1393 describing how O’Maelachlainn and his allies successfully attacked and broke down the castle of Baile Bhaiter, as Waterstown was then known. The strategic importance of this island fortress becomes clear when considering its position in the centre of the lake, which would have provided natural defences against would-be attackers. The 1837 Ordnance Survey maps reveal just how dramatically the landscape has changed, showing a substantial body of water where now only wetlands remain.

Archaeological surveys conducted in 1981 documented not only the tower’s remains but also intriguing traces of horizontal wooden beams visible off the northern shoreline of the island. These timbers may be remnants from the castle itself, or perhaps evidence of earlier structures, possibly even relating to the suspected crannóg beneath. The layering of history at this site; from potential prehistoric lake dwelling to medieval stronghold to overgrown ruin; tells a story of continuous occupation and adaptation spanning centuries of Irish history.