In the shadow of Montpelier Hill, where the infamous Hellfire Club once echoed with laughter and ritual, stands a quieter but no less mysterious building — Killakee House.

The story begins around 1765, when the Conolly family of Castletown House built a steward’s residence on their vast Dublin Mountains estate. In the early 1800s, Luke White, a wealthy bookseller and politician, purchased the property and over 3,500 acres of surrounding land. Soon after, he constructed a magnificent Georgian mansion at the centre of the estate — a three-storey house of elegance, adorned with rose terraces, fountains, and glasshouses.

By 1880, the estate passed by marriage into the aristocratic Massy family, making it the Dublin seat of Lord Massy. For a time, life at Killakee was a picture of privilege. John Thomas, 6th Baron Massy, hosted lavish shooting parties and woodland picnics, complete with fine china, gourmet food, and liveried servants.

But prosperity has a way of fading. By the early 20th century, extravagance had turned to debt. The family’s fortunes collapsed, and by 1924, the estate had passed to Hugh Hamon Massy, the 8th Baron, who could no longer stave off ruin. Reduced to living in the old steward’s house, he famously feigned illness to delay the inevitable — only to be carried out on his mattress when the bailiffs came.

The grand Georgian house was stripped by vandals and, by 1941, demolished for salvage. Yet the steward’s house survived — and in time, it inherited the name Killakee House.

The Dark Awakening

For decades, the property stood silent. But in 1968, Margaret and Nicholas O’Brien acquired the old residence, intending to transform it into an arts centre and tearoom. Their plans, however, soon took a sinister turn.

As renovations began, workers complained of an unnatural chill in certain rooms, tools moving by themselves, and doors that refused to stay locked. Some heard a disembodied voice whispering, “You cannot see me, but I can see you.” Several labourers quit the job altogether.

At night, Margaret herself heard terrifying noises while alone in the house — her dogs restless and barking at unseen intruders. Objects were found moved or overturned, though the property was securely locked.

The Black Cat of Killakee

If you’ve heard the tales of the Hellfire Club, you’ll know of the demonic black cat said to prowl Montpelier Hill — a creature linked to the club’s occult rituals. It seems the same entity may have found its way down the hill.

One evening, a carpenter working late witnessed the heavy door swing open, and in walked a huge black cat “as big as an Alsatian”, with glowing red eyes fixed upon him. Over the following nights, more workers reported seeing the same creature.

The artist Tom McAssey, a friend of the O’Briens, later saw the cat himself while painting a mural inside the house. He immortalised the vision in his now-famous portrait of the Black Cat of Killakee, which hung in the property for many years.

Some accounts claimed the cat was accompanied by the spirit of a small, disfigured man, said on one occasion to have transformed into the feline before vanishing.

During further renovations in 1971, a tradesman uncovered the skeleton of a small human on the grounds — a discovery that fueled rumours of human sacrifice tied to the Hellfire Club’s rituals.

Ghosts and Apparitions

The O’Briens’ experiences did not end with the cat. Throughout 1969, guests reported seeing a tall man in a black cloak, believed by some to be the spirit of a priest who once tried to banish the demon.

Two phantom nuns, pale-faced and hollow-eyed, were also seen drifting through the halls. A clairvoyant identified them as “Blessed Margaret” and “Holy Mary”, said to have taken part in black masses on the hill centuries earlier.

A blood-soaked man was sometimes seen upstairs — his apparition linked to a violent 1922 incident when Anthony Harmon, a local man, was shot dead in the house during the Civil War.

The O’Briens endured violent noises, shattered pottery, and ripped canvases. One family member was reportedly pushed down the stairs by unseen hands. Even after a priest blessed the house in the mid-1970s, reports of cold spots, disembodied whispers, and poltergeist pranks persisted.

Eventually, the O’Briens left. Killakee House lay abandoned for years before reopening as a restaurant, and later as a café — both of which have since closed.

In 2020, while the property was still in operation, a manager reported that some customers had described a ‘bad feeling’ in one area. Another said that they had seen the ghost of a smallman with a curved spine standing in one of its rooms.

Today, the property is privately occupied and closed to the public.