<P> Nora tells the other guests that she shot Loren in the basement, but when they all arrive there they find him alive . He tells Nora that the gun she fired at him had been loaded with blanks, and explains to his guests that his wife and Dr. Trent had been trying to kill him and that they have each met their end in the vat of acid, adding solemnly that he is "ready for justice to decide" his guilt or innocence . </P> <P> Watson Pritchard, still an avid believer in the supernatural, looks into the acid and declares that Annabelle and Dr. Trent have now joined the ranks of the house's many ghosts . With a terrified expression on his face, he announces that the ghosts are now coming for him, then, he turns toward the audience and adds, "And then they'll come for you ." </P> <P> While exterior shots of the house were filmed at the historic Frank Lloyd Wright - designed 1924 Ennis House in Los Feliz, California, the bulk of the film was shot on sound stages, depicting the interior of the house in a combination of styles, including 1890s Victorian, with gas chandeliers and sconces . The poster for the film included an illustration of a house in yet a third style, that of a fanciful four - story Romanesque structure . </P> <P> The theatrical trailer promoted the film as The House on Haunted Hill, although all advertising material and the title on the film itself were simply titled House on Haunted Hill . </P>

House on haunted hill where was it filmed