This tower house, which appeared on the 1654-7 Down Survey map within a defensive bawn wall, was built on high ground near the Camoge River. Though no trace of the structure survives today, historical records paint a picture of a castle with a complex history stretching back to the late 12th century, when it may have been the fortification granted to John de Grey in 1199.

The castle’s various names tell their own story. It was dubbed the ‘Black Castle’ to distinguish it from the nearby White Castle to the east, and both structures were marked on the Down Survey map alongside the ‘Towne Green’, which sat in the field immediately west of the church ruins. By 1583, the castle was already described as completely ruined except for its stone walls and a great enclosure called the ‘balne’ or bawn; a fortified courtyard typical of Irish castles. Despite its ruined state, the property continued to change hands through the centuries, passing from the Apsley family in 1589 to F. Fitton in 1627, and later to various members of the Grady family before being sold to Richard Coote in 1655.

The castle’s connection to the powerful Earls of Desmond gave it particular significance in local history. By 1703, what remained of the estate had been purchased by Alderman B. Burton after belonging to James FitzGerald. Though 18th-century historian FitzGerald described it as ‘noble ruins of a castle on the river, erected by the Earls of Desmond’, the structure was eventually levelled entirely. The 1837 Ordnance Survey map still marked its location as ‘Desmond Castle’, preserving the memory of this once-important fortification that played a role in the complex tapestry of medieval and early modern Irish history.