Just east of the Hellfire Club on the slopes of Mount Pelier, opposite the entrance to Massey’s Wood is a private residence once known as the Stewart’s House. This area around The Hellfire Club is one of the most notorious haunted locations in Ireland. It is said that the Hellfire Club was cursed because it was built on the site of an ancient Stone Age burial cairn using rocks from the cairn in its construction.

This Stewarts House was part of the former Lord Massey’s estate and has its own ghoulish story. Hugh Massey squandered his wealth and the banks repossessed his vast ancestral home once called ‘Killakee House’ and it was subsequently demolished. Following the demolition the Stewarts House became known as ‘Killakee House’. In the 1960s and 1970s it was believed that this house was haunted. Many uncanny happenings, violent events and mysterious phenomena took place there. The house is linked to activities that took place in the Hellfire Club and was used by the Hellfire Club members on several occasions before and after their nocturnal activities on top of Mount Pelier.

Local legend tells how Richard "Burnchapel" Whaley, a local member of one of the richest families, and a regular member of the club revelled in the debauched rituals. They are said to have included burning black cats alive and the worshipping of cats in place of Satan himself.

The ghost of a woman screaming in anguish has also been reported in the area. It is believed that she was murdered by being trapped in a barrel, which was then set alight and rolled down the hill while the young aristocrats of the club laughed.

Additionally Killakee House and the nearby Hellfire Club was said to be haunted by the spirit of a young man, a dwarf, who was brutally murdered in the Eighteenth century, during a ritual at the Hellfire Club. Giving credence to the rumors in 1971 the body of a dwarf was found buried under the kitchen of Killakee House alongside a grotesque effigy of a horned and tailed demon.

There have been other noted visitors who stayed in the house. Countess Markievicz spent some time in the house in the years before the 1916 uprising. During the troubles in the 1920's a gun battle between the IRA and Black and Tans took place there, killing five members of the newly-formed IRA.

After a period of disuse the derelict building was purchased by Margaret O’Brien and her husband, in 1968. They planned to renovate it and open it as a Tea Rooms and Arts Center. Little did they know that it was already inhabited by a ghostly creature. Workmen restoring the house were terrified by numerous sightings of a huge black cat, said to be about the size of a dog with gleaming red eyes. Additionally there were other disturbances including locked doors opening by themselves. Many of the workmen left without even collecting their wages and they refused to stay in the house. It fell to friends and family to finish the work.

At first Mrs. O Brien thought the whole thing was nonsense, until she saw the creature for herself. She said the animal was about the size of an Alsatian and that it squatted on the flagstones in the hallway. All the doors were locked before the apparition appeared and they remained locked after its disappearance.

One evening an artist known as Tom McAssey and two other men were painting the main hall and another room when the temperature dropped alarmingly. They were shocked to find the heavy 18th century door swinging open, revealing swirling mists, especially as they had locked it earlier that evening. McAssey was further unnerved by the sight of a shadowy figure on the doorstep who spoke in a menacing guttural voice warning them that the door must not be closed.

As they fled, the figure in the hall changed form . He described it as “A monstrous black cat with red-flecked amber eyes crouched there in the half-light “

Later McAssey painted a portrait of "The Black Cat of Killakee" which still is in the house today.

There were further sightings of the infamous Black Cat of Killakee in the area. Locals felt it was not the spirit of a cat, but rather a terrifying elemental spirit. Those who have encountered it report that it is capable of speech, and has a face that can only be described as disturbingly humanoid

Locals were not the only ones to see the apparitions of the cat or the dwarf boy. In the 1970s a series of séances and Oujjia board sessions were carried out in an attempt to lay the ghosts to rest. However the disturbances accelerated and worsened. Lights turned on and off independently, furniture was broken into pieces during the night and bells were heard ringing. The dwarf boy was seen walking with a bloodstained man.

In fact RTE made a short programme about the goings on in an attempt to catch the poltergeist at work but all was quiet on that day. The following day was a different story altogether: a sticky substance oozed throughout the house. The O’Brien’s new pottery was smashed and paintings were torn to shreds. In the following days different types of caps materialized on the floor and chairs: babies caps, sun caps, woolly hats and women’s hats. Some contained coins from France and Poland. In 1977 a priest exorcised the house and all haunting ceased, at least for the time being.

After the Arts center opened guests stayed there frequently. One night, a group of actors a little the worse for drink held a séance there, as they had heard rumors about the cat locally. The cat was soon back, as well as the ghosts of two nuns that would pop up unexpectedly from time to time, confronting guests in the gallery. A medium visited soon after, and claimed that the spirits were those of women who had assisted in satanic rituals done by the notorious Hellfire Club.