The film features three actresses who appeared in Hammer Horror Productions during the British studio's heyday: Jane Merrow Hands of the Ripper (1971), Caroline Munro Dracula A.D. 1972 (1972), and Judy Matheson in Lust for a Vampire (1971) and Twins of Evil (1971).
The hauntings at Margam Castle have previously been the subject of three television shows: Most Haunted (2002) , Ghost Hunters (2004), and Margam Castle (2019).
Margam Castle is reported to be one of the most haunted buildings in Wales. It has been the subject of countless paranormal investigations in the UK. Some of the rooms in the castle were boarded up and closed off in 2008 due to the reported activity and concerns over safety. The most frequently encountered spirit is Robert Scott a gamekeeper who worked at the Castle for many years. Scott was murdered by a poacher and it's said his spirit can often be seen purposefully ascending the Gothic staircase near the entrance way to the Castle. His presence has regularly connected with psychic investigators, all of whom insist his spirit is consumed with rage over his unjust killing.
Filming took place entirely on location in South Wales. The primary locations for the film were Margam Castle near Port Talbot, Llanthony Secunda manor house in Caldicot, the Rock and Fountain public house and Glyn-Yr-Mur Farm in Aberdulais, Neath Town Hall, Loughor Town Hall in Swansea, Millennium Quay in Llanelli and some exteriors in Tonna.
Staying at Secunda Manor, during the shooting of The Haunting Of Margam Castle, actress Sara Dee (Catherine the Bride) witnessed paranormal activity in her bedroom on the first floor and documented her Secunda Manor Story on film.