The lake, known as ‘Clam Lough’ on the 17th-century Down Survey barony map, provides a scenic backdrop to this rectangular fortification that has witnessed centuries of conflict and change. The castle appears on that 1656-8 map as what might be two towers, offering a tantalising glimpse of its original form.

This was once the house of Mael Sechlainn MacRaighnaill, and in 1473 it became the scene of a violent attack when Tadhg MacRaighnall assaulted the stronghold, leaving fourteen men dead. The castle’s strategic position near the lough likely made it both defensible and desirable, though it couldn’t prevent this particular tragedy. By 1750, an estate map described it as ruins, though the accompanying notes optimistically suggested it might be easily repaired; a prediction that proved accurate, as the remains have since been conserved.

The structure that survives today is a compact rectangular building measuring 10 metres north to south and 7 metres east to west, with distinctive battered walls and rounded corners that rise to about 7 metres in height on the north and west sides. The southern and eastern walls have fared less well, standing only 1.5 to 3 metres tall. Visitors entering through what was once a doorway on the south wall would have passed through a lobby before reaching the ground floor, which still shows remnants of an east-west barrel vault. Simple windows pierce three of the four walls, whilst a mural staircase rises eastward from the entrance lobby. The castle caught the eye of artist Daniel Grose in the late 18th century, who captured its appearance in an illustration that provides valuable evidence of its condition during that period.