The real life location which portrayed "The House in Nightmare Park" was the Victorian Gothic house called Oakley Court which was situated near Bray Studios.
According to Daz Lawrence at the website 'Horrorpedia', this movie was the one that its star Frankie Howerd "was most fond of".
The picture was a spoof and parody of both the 'Old Dark House' genre and the British Hammer Horror movie of which only Carry on Screaming! (1966) had really preceded it.
Frankie Howerd, whilst on a trip to Los Angeles, persuaded veteran American actor Ray Milland to be in the movie.
Some movie posters were partially styled in true music hall tradition inviting "ladies and gentlemen" to see this picture "for your horrification". Moreover, jokingly, the posters also advertised the film by saying "Don't See It Alone - Bring The Children".