The square tower rises approximately 50 to 60 feet from its rocky foundation, which itself sits atop a substantial limestone platform measuring 60 to 80 metres across. With internal dimensions of roughly 26 by 24 feet spread across four storeys, this defensive structure commands an impressive view of the surrounding countryside, a strategic advantage that would have been invaluable to its various inhabitants over the centuries.

The castle’s documented history reveals a succession of notable occupants, beginning with the Bourke family who were said to have made it their residence. By 1583, records show W. Bourke holding Ballynacarrig Castle, though ownership had shifted by 1600 when James Gould controlled what was then referred to as both Ballynecarrygie and Rockstowne. The tumultuous period of the 1650s saw Captain G. Ingoldesby in possession of the castle and its bawn, the fortified enclosure that would have provided additional protection for livestock and residents during times of conflict.

The structure attracted the attention of Victorian antiquarians, with Thomas Johnson Westropp documenting its features in the early 1900s and the artist Du Noyer capturing it in sketches now held by the Royal Society of Antiquaries of Ireland. Despite the passage of time, the tower remains remarkably well preserved, its four storeys still intact; a testament to medieval Irish construction techniques and the enduring nature of these limestone fortifications that dot the Irish landscape.