Bloody Pit Of Horror/Il Boia Scarlatto (1965)

Writer Rick and his publisher Daniel Parks finally find the ideal location in Italy to shoot some photographs for Rick's Horror photo-novel when they come across an ideal spot. The seemingly deserted castle looks perfect from the outside, so Rick and Daniel, accompanied by his secretary Edith, their photographer Dermott, and his five young models decide to break in. They soon find the castle is actually occupied by former actor, Travis Anderson, who initially is annoyed with these visitors until he recognises Edith, his ex-fiancèe amongst them. He decides to give them permission to use his castle, but warns them that the dungeons are off limits.

IMDb: https://www.imdb.com/title/tt0058983