The rectangular tower, measuring 14.5 metres north to south and 8.6 metres east to west, is now heavily draped in ivy, with its walls standing largely intact up to wall-walk level, except for the southern wall which has significantly collapsed. This damage isn’t entirely due to age; much of it resulted from Lord Castlehaven’s bombardment during a siege in 1645, though 19th-century quarrying for building stone also took its toll on the structure’s south side.

The castle’s defensive architecture reveals sophisticated medieval engineering. Entry was through a door in the now-damaged south wall, leading into a vaulted lobby complete with a murder hole above, from which defenders could attack unwelcome visitors. The lobby opens into the main ground floor chamber, measuring roughly 8 by 4.5 metres, whilst a smaller eastern chamber houses the beginning of a spiral staircase that winds its way to the tower’s summit. Each floor showcases different architectural features, from gun loops and narrow defensive windows on the lower levels to more elaborate ogee-headed windows higher up. The first and third floors retain their impressive rounded vaults, whilst various mural chambers, including what appear to be garderobes and a possible bread oven converted from a blocked window embrasure, demonstrate how the castle balanced military necessity with domestic comfort.

Built by a branch of the Fitzgerald family of Imokilly, Kilnatoora Castle retains evidence of its original defensive perimeter. Early 19th-century illustrations by antiquarian Daniel Grose show a round corner tower to the south of the main tower house, connected by sections of bawn wall, though these features are no longer visible today. The castle has been protected as a national monument since 1933, and from its position roughly 800 metres southeast of Cornaveigh Castle, it forms part of a network of fortifications that once controlled this strategic valley. Despite centuries of weathering and human interference, the tower remains an impressive testament to the turbulent history of County Cork’s medieval landscape.