McSwyne's Castle, also known as Rahan Castle and Castle Murray, is a 15th-century fortification near Dunkineely on St John's Point in County Donegal. Built by the McSwyne family, likely Argyllshire mercenaries who became Clan Suibhne stronghold keepers, the castle passed to William Stewart after the Plantation of Ulster and later to John Murray, favourite of King James VI. Though now a ruin with only a chimney stack, two gables, and a wall surviving, it remains a notable landmark illustrating the complex ownership disputes that followed the 1641 rebellion.
