Site of Ballynahoogh Castle, Cavetown Or Ballynahoogh, Co. Roscommon

First demolished by Aedh Roe O'Donnell in 1487, the castle originally belonged to the sons of Rory Mac Dermot. The Mac Dermots quickly rebuilt their stronghold in 1492, though possibly at a different location, only to see it repeatedly attacked over the following decades. The Earl of Kildare plundered it in 1512, and O'Donnell returned to capture and destroy it once more in 1527, demonstrating the castle's strategic importance in the contested borderlands between Connacht and Ulster.

The violence continued well into the 16th century when, in 1562, the Sliocht Eoghan faction brought gallowglasses; elite Scottish mercenary warriors; into Moylurg and burned Ballynahoogh during their power struggle with their uncle Rory. By this time, the castle and its lands had passed to descendants of Dermot Ruadh of Tir Tuathail, with ownership confirmed to Cathal Mac Fergainm in 1617. However, the castle's days were numbered; by 1635, it was described as 'ruinated' and the lands had reverted to Terence Mac Dermot of Carrick of the Rock.

Today, nothing remains visible of this once contested fortress. The castle stood on a rise overlooking a stream that connects Clogher Lake to the north with Cavetown Lough to the southwest, about a kilometre from the later Moylurg Castle. When antiquarian John O'Donovan visited in 1837, only slight traces remained, and whilst the Ordnance Survey maps of that year show a shell measuring roughly 10 metres north to south and 5 metres east to west, even these vestiges have since vanished beneath a coniferous wood. A crannog in nearby Cavetown Lough serves as one of the few remaining medieval features in this historically rich landscape.