Located in Birr in County Offaly, the fortress was originally the home of the powerful O’Carroll family. Sitting in a commanding position facing the Great Pass through the Slieve Bloom Mountains to the province of Munster, it was built in 1250 to act as the family’s main stronghold.
The castle, with walls nine feet thick, is said to have witnessed a number of gory murders over the centuries. One of the most gruesome took place in 1532 in a room now known as the Bloody Chapel. A bitter dispute came to an end when one of the O’Carrolls drove a sword into the back of a priest as he held mass - the priest was the murderer’s brother and the victim is said to haunt the chapel to this day.
In 1922, workmen uncovered a secret dungeon full of human skeletons amassed on top of wooden spikes. It is thought they were probably prisoners sent to their deaths via a trap door. A horrific act of treachery also saw an entire 40-strong clan poisoned to death even though its members had helped the O’Carrolls in battle.
However, the castle’s most famous, and most evil, supernatural resident is an elemental spirit whose apparition is said to be accompanied by the rotting stench of a decomposing corpse and the smell of sulphur.