. . "Mongavlin Castle also known as Mongevlin Castle is a ruined castle on the west bank of the River Foyle, approx 3 km south of St Johnston, County Donegal, Ireland.It was once a stronghold of the O'Donnell's, Lords of Tyrconnell.In the sixteenth century Mongevlin was the chief residence of Ineen Dubh, she was the daughter of James MacDonald, 6th of Dunnyveg, and mother of Red Hugh O'Donnell.The State Paper recording her possession of the castle: \" From Cul-Mac-Tryan runs a bogg three myles in length to the side of Lough Foyle in the midst of the bog is a standing loughe called Bunaber here at Bunaber dwells O'Donnell's mother (Ineen Dubh M'Donnell). "@en . . "Mongavlin Castle"@en .