The castle, which appears on Ordnance Survey maps from 1842 and 1920, crowns a hilltop surrounded by rolling, hazel-covered countryside. Historical records from the area mention one or two castles in Glencolumbkille, though scholars remain uncertain whether these documents refer to this particular fortress, another tower house in neighbouring Glencolumbkille South, or perhaps both structures.

What’s certain is that a castle called ‘Glancollayn Kelly’ was owned by the O’Loughlin clan in 1574, marking it as part of the complex web of Gaelic lordships that dominated the region. Following the 1641 rebellion, the castle was confiscated by British forces and granted to John Blake and his wife, before being rented out to John Hynes and Brian Kilkelly in 1659; the last documented mention of the fortress. Today, only fragments of the northwestern wall survive, standing about three metres high and constructed from medium-sized, roughly dressed stone blocks. The wall preserves intriguing architectural details including a broken garderobe aperture with an intact chute, a single corbel, and remnants of vaulting that once supported upper floors.

Archaeological investigation has revealed traces of an internal wall extending southeast from the main structure, complete with part of a doorway that may have separated the main ground floor chamber from a porter’s lodge. Whilst the southeastern wall lies buried beneath rubble and the northeastern and southwestern walls have vanished entirely, the site remains remarkably evocative. A medieval house sits approximately six metres to the southeast, whilst a small stone shed to the northeast, though likely much later in date, appears to have been constructed using stones robbed from the original tower house; a common practice that speaks to the castle’s long afterlife as a convenient quarry for local builders.