Now incorporated into a working farmyard alongside the 19th-century Blackhall House, this Eustace family stronghold has suffered considerable damage; the entire eastern half collapsed sometime before 2004, leaving only the western portion standing amidst mixed farmland and pasture. The surviving structure measures approximately 12.4 metres north to south and 8.2 metres east to west, its remarkably thick limestone walls, some reaching 3.3 metres in thickness, still bearing witness to its defensive origins.

The castle’s intricate internal layout reveals the sophistication of its original design, with narrow intra-mural passages, chambers and a spiral staircase cleverly built within the massive walls themselves. The ground floor features a vaulted chamber accessed through a narrow passage in the south wall, whilst the southwestern corner houses a spiral staircase that once connected all four floors. Each level contained its main chamber along with smaller rooms tucked within the walls, including cupboards, garde-robes and what appears to have been a double-height vaulted chamber spanning the first and second floors. Fireplaces can still be traced in the northern and western walls, with one partially brick-lined flue rising through multiple storeys, whilst blocked windows and doorways hint at the castle’s former fenestration pattern, including at least one twin-light, ogee-headed window that once graced the third floor.

Perhaps the most intriguing artefact associated with Blackhall Castle is a Sheela-na-gig, a medieval stone carving of a female figure, which originally stood beside the entrance. When the eastern section collapsed, this remarkable carving was rescued from the rubble and carefully preserved; it now resides in a specially created niche in the interior of the north wall, continuing to guard this atmospheric ruin as it has for centuries.