Filmed on the Ellis Estate in Scituate, MA where another Italian horror film, Ghosthouse (1988), was filmed.
Third part of Lucio Fulci's "Gates of Hell" Trilogy. The other two films include: City of the Living Dead (1980) and The Beyond (1981).
One of the early VHS issues of this film in America had several of the film's reels out of order, further confusing the already erratic story.
Although most of the dialogue was done in English (the two children's dialogue is in Italian), the movie was nonetheless dubbed in post-production.