This unusual fortification combines elements of both 13th-century hall houses and later medieval tower houses, making it something of an architectural oddity. The main structure consists of a three-storey rectangular tower measuring 12 metres north to south and 10 metres east to west, with two corner towers added at different periods; a four-storey tower at the southeast corner and a five-storey tower at the northwest, the latter featuring garderobe chutes that exit near ground level.

Entering through the remains of the ground-floor doorway on the west wall, visitors can still see fragments of the original wicker-centred arch and portcullis slot above. The ground floor chamber, measuring roughly 8 by 6 metres, was lit by windows in all four walls, though the north window is now blocked and the east window has been robbed out, leaving a substantial breach. Above this, the first floor retains part of its pointed barrel vault, whilst the second floor showcases decorative arcading along three walls and multiple windows, including a particularly wide central window in the east wall. The southeast tower has largely collapsed and become overgrown, whilst the northwest tower preserves evidence of its five storeys, complete with narrow spiral stairs and garderobe chambers on multiple levels.

The castle’s history remains somewhat murky, though records show that ‘Ballym’Phillipp’ was included in a 1588 grant of land to Arthur Hyde, along with substantial portions of the Condon family territory. The Down Survey of 1655-6 depicts Ballymacphilip as a detached portion of the Barony of Condons and Clangibbon. Architectural historians suggest the building’s elongated form and portcullis mechanism point to an earlier construction date than typical tower houses, likely representing a transitional form between the hall houses of the 13th century and the more familiar tower houses that dominated the Irish landscape from the 15th century onwards.