When antiquarian J. O'Donovan documented it around 1838, this mysterious structure was already reduced to a stump, though it still retained enough of its form to tell a story. Rising 12 feet high with substantial walls measuring nearly 30 feet by 24 feet and six feet thick, the remnant even preserved its vaulted roof; a testament to the skill of its medieval builders.

The structure's true purpose remains something of a puzzle. While O'Donovan carefully recorded its dimensions, converting to roughly 12 metres by 7.5 metres in modern measurements, no other historical records mention this particular building. Its proximity and alignment with Rathgormuck castle suggest it may have served as a corner tower of the bawn, the defensive wall that would have enclosed the castle complex. These fortified enclosures were common features of Irish tower houses, providing an outer line of defence for livestock, supplies, and the families who depended on the castle's protection.

Today, farm sheds occupy the spot where this enigmatic structure once stood, leaving only the written observations from the 1841 Ordnance Survey to preserve its memory. The account, later compiled by M. O'Flanagan in 1929, represents one of countless architectural casualties of Ireland's turbulent history; buildings that survived centuries of conflict only to vanish quietly beneath the practical needs of agricultural life. What remains is a tantalising glimpse of Rathgormuck's former extent, when the castle complex sprawled beyond the single tower that survives today.