When English surveyors documented the site in 1622, they found ‘an old ruinous bawn of lime and stone’, a defensive courtyard measuring 60 feet square with walls still standing 8 feet high. The castle itself, though roofless and floorless by then, measured 30 by 20 feet and clung to one side of the fortification. This strategic position overlooking the harbour made it an ideal defensive stronghold for the McSwyne clan, who controlled much of this part of Donegal during the medieval period.

The castle’s military significance extended well beyond its original builders. In the early 18th century, the East India Company recognised the site’s tactical value and installed a battery here to guard Killybegs harbour; a reminder that even Ireland’s western shores played a role in Britain’s global maritime ambitions. By 1848, however, time and neglect had reduced the once proud fortress to little more than foundation courses visible amongst fallen rubble. The final indignity came around 1763, when local tradition holds that stones from the medieval castle were carted away to build the new Catholic church in the town.

Today, visitors to Castle Point will find no dramatic ruins or photogenic towers, just a grassy headland with spectacular views over Killybegs harbour. The name itself is now the most tangible reminder of the fortress that once stood here, watching over one of Ireland’s finest natural harbours. The site serves as a poignant example of how completely even substantial stone buildings can vanish from the landscape, their stories preserved only in place names and the careful notes of antiquarian scholars.