Taaffe's Castle lies in the town of Carlingford, in County Louth, in Ireland.
Taaffe's Castle was built as a fortified town tower house in the early 16th century by a rich merchant family; the Taaffe's. Its close proximity to the old harbour would suggest a trading depot of some kind occurring on the ground floor with the upper floors reserved for residence.
The rectangular tower house is 4 storeys high plus the roof walk. It has a projecting turret at the south-west corner. The original entrance was in the western wall beside the turret. It was protected by a small machicolation. To the left of the entrance a short passage led to a spiral staircase in the north-west corner. This led to the second floor and was protected by a murder-hole. Another spiral staircase in the south-west corner led from the second floor to the roof. There are garderobes at 3 levels in the north-east corner. The tower is vaulted above the first floor.
Later in the 16th century a 2 storey rectangular addition was built against the northern wall.
The Taaffe family became Earls of Carlingford in 1661 and Nicholas Taaffe fell at the battle of the Boyne in 1690. The Taaffe family later emigrated to Austria.
I don't know when the castle was abandoned but the town of Carlingford was described to be in a state of ruin in 1744, so maybe that's when the castle fell to ruin.
When I visited Taaffe's Castle seemed not to be used for anything. From someone who visited the castle in 2011, I learned that the castle is now used as a pub. The town of Carlingford is a little bit touristy and there are two more castles in town; The Mint (another 16th century tower house which I didn't visit) and Carlingford Castle (more commonly known as King John's Castle).