By the time of the Civil Survey in 1654–6, this structure was already described as ‘an old little castle ye walls onely standing’, suggesting it had seen better days even then. The land around Ballycolliton had a complex ownership history; it was divided between several landowners including Sir Nicholas White, who had purchased his portion from Edmond Kenedy before the Rebellion, John Hurly, who bought his share from Mortagh O’Bryen of Annagh, and Rory Kenedy, who inherited his portion from his ancestors.

What remains today is a small rectangular tower house measuring 6.3 metres southwest to northeast and 4.75 metres northwest to southeast, with walls about 1.5 metres thick. Built from roughly coursed limestone rubble with a characteristic base batter, the tower survives to three storeys, though it may originally have stood a storey higher. The structure shows clear signs of later modifications; nineteenth-century outhouses were attached to three of its faces, whilst a large water tank and bellcote were added to its top during the same period. The current flat-headed doorway in the centre of the southeast wall probably replaced an earlier entrance, leading to a ground floor now filled with debris where only a destroyed fireplace in the eastern angle remains visible.

The upper floors reveal more about the tower’s original layout and features. The first floor, which once had a wooden ceiling like the ground floor below, contains a fireplace whose flue connects with the one below. Mural stairs built into the southeast wall lead up to a barrel-vaulted second floor, accessed through a flat-headed doorway. This level was originally lit by windows set into large segmental-arched embrasures where wicker centring is still visible, though the windows themselves are now blocked. The tower features various window styles including flat, round and ogee-headed single lights, whilst slop-stones along the mural stairs provided basic sanitation. A possible bawn wall or forebuilding attached to the northeast angle suggests this was likely a seventeenth-century tower house, a typical defensive residence of the minor Irish gentry of that era.