Clotworthy House was constructed c1843 by the 10th Viscount Massereene, and originally served as an ornate stable block serving Antrim Castle. It was later converted for residential use but has served as an arts centre since 1982.

In 1993, a security guard heard noises coming from inside the locked up building on five consecutive nights. For four nights, he went to investigate, believing that there was an intruder hiding inside, but he found the building to be completely empty each time. However, on the fifth night he saw a figure standing in one of the rooms. As he prepared to approach, the figure simply vanished into thin air.

Speaking of his encounter, the guard affirmed:

I’ve been in this line of work for years and have sat in lots of deserted buildings at night. I haven’t got an imaginative mind and I know what I saw and what I heard. So take it or leave it. For those who believe, no proof is necessary. For those who do not, no proof is possible.

Some believe that the figure he had seen was the ghost of Ethel Gilligan, a 19-year old servant who perished during the fire at Antrim Castle in October 1922. Her form has also been seen in the castle gardens on many occasions.