The main rectangular tower, measuring 9.7 metres east to west and 7.5 metres north to south, is accompanied by a seven-storey stair tower projecting from its northeast corner and a three-storey addition on the eastern side. Remnants of the original bawn wall survive to the north and west, complete with a circular flanking tower in the northwest corner that features numerous gun loops and a distinctive dome over its ground floor chamber.

The castle’s interior reveals a fascinating blend of medieval construction and 19th-century renovation, much of it undertaken by Lady Listowel after 1838. Entry is gained through a pointed-arch doorway in the eastern tower, protected by a low machicolation overhead and featuring a yett-hole at its apex. Inside, visitors would find chambers lit by mullioned windows with square hood mouldings, many inserted during later rebuilding campaigns. The ground floor retains its original low, segmental vault, whilst upper floors feature wooden panelling and plasterwork from the Victorian renovations. Notable architectural details include a round-headed piscina on the third floor, suggesting the presence of a chapel, and several impressive fireplaces, including one on the third floor with joggled voussoirs bearing the inscription ‘M L Restored 1862’.

Originally a Condon manor, Ballyhooly passed to the Roche family in the 14th century before being forfeited and granted to Sir Richard Aldworth. The castle’s defensive features, from its gun loops to its commanding position above the river valley, speak to its strategic importance through turbulent centuries. Today, whilst some elements like the 19th-century crenellated parapets and bellcote are relatively recent additions, the structure remains a remarkable example of how Irish tower houses evolved and adapted through the ages, transforming from military strongholds into country residences whilst retaining their essential character.