What remains today is the square bawn, measuring approximately 32 metres east to west and 36 metres north to south, along with two of its original four corner towers in the southeast and southwest positions. These towers showcase an intriguing design feature; whilst their interiors are perfectly circular, each tower has an angular projection on its outward-facing side, creating a unique defensive profile. Originally standing three storeys tall, the towers were accessed via external wooden stairs within the bawn, with each level having its own doorway. The first floor of one tower still retains a fireplace with punch-dressed jambs and drafted margins, whilst at ground level, two small rectangular windows flank what was once a doorway.

The south wall of the bawn holds particular interest, featuring a machicolation and rectangular chimney stack at first-floor level; these may be the sole surviving remnants of the fortified house that once stood within. The machicolation likely defended an entrance to the house itself. The original entrance to the bawn was located at the eastern end of the north wall, though this has since been destroyed. Above this entrance once sat a date stone marking 1649, noted in surveys from 1942 but now removed. The castle gained historical significance when the papal nuncio Rinuccini visited in 1648 whilst travelling from Kilkenny to Galway, marking it as an important Mac Coghlan stronghold during this turbulent period.

The most tragic chapter in Kilcolgan’s history occurred in the 1950s when the Electricity Supply Board demolished the fortified house to provide rubble for a nearby power station. Fortunately, photographs in architectural archives preserve its former glory, showing an L-plan fortified house standing two storeys high, complete with a crenellated wall walk, distinctive Jacobean chimney stacks, and elegant transomed and mullioned windows. These images serve as a poignant reminder of what was lost, transforming what could have been one of Ireland’s more complete plantation-era fortifications into the evocative ruins that stand today.