The Prendergast family held this spot from at least the mid-16th century, and by 1640, Edmund Prendergast had inherited not just the castle and its surrounding 60 acres, but an additional 120 acres at nearby Ballyteskin. The Civil Survey of 1654-6 confirms these holdings within Whitechurch parish, painting a picture of a modest but strategically positioned estate.

The tower house itself is a compact rectangular structure, measuring roughly 7.4 metres east to west and just over 7 metres north to south. Built with granite quoins at its corners, it originally rose three storeys high, though today it survives only to the string course where the wall walk would have begun. The western entrance, now destroyed along with its protective murder hole, once led into a lobby that provided access to both the ground floor chambers and a spiral staircase built into the northern wall. This mural stair wound its way up through all three floors, connecting spaces that became progressively more comfortable as they rose; the ground floor had only defensive embrasures, whilst the first floor gained a window, and the second floor boasted a proper fireplace, garderobe, and multiple chambers.

The most intriguing architectural detail is found in the northern wall, where weathering marks and a blocked passage suggest that another structure, likely a fortified house, once stood attached to the tower. The third floor, now partly obscured by later brick vaulting, would have provided access to the wall walk through an awkward arrangement; defenders would have climbed three steps within the eastern wall passage before hauling themselves up through an opening in its roof. This somewhat ungainly design speaks to the practical challenges of fortifying a relatively modest tower house, where every square metre had to serve multiple purposes of defence, storage, and daily living.