Nightmare Castle is a 1965 Italian horror film starring Barbara Steele. Mario Caino directs. The music is by Ennio Morricone, an Academy Award-winning composer who did the music for the Man with No Name trilogy and others.
You can watch it from the Internet Archive or via Youtube:
1000 Misspent Hours doesn't like it but doesn't know whether to blame the film itself or that particular DVD. Images Journal has an article examining this film. BrainEater discusses the background, saying that "Nightmare Castle does a credible job of bringing together different elements of Gothic horror."
7/2/2009: WTF-Film has a review.