The dining room of Palais des Thermes (Ostend) with the coloured glass wall representing the sea with seagulls, where Valerie and Stefan are eating the first evening and where countess Bathory sees them for the first time, still exists but the trinkhall (300 meters from the hotel) with the seduction scene between countess Bathory and Valerie ("little Edelweis") is no longer there. The entrance hall is at Hotel Astoria (with the conversation with Pierre and where countess Bathory is knitting), but the rooms and windows are shot at the Grand Hotel des Thermes. If countess Bathory has been there 40 years ago, this is not probable because the hotel is build only in 1932 and the action takes place in 1970...
Shot entirely in English, even though the majority of the cast was French, German and Flemish. As opposed to most European "genre" films from the 70s, here none of the actors were post-dubbed by others. They can all be heard with their own voices (resulting in some accents), notably Delphine Seyrig's deep, smoky voice or Andrea Rau's and Paul Messer's German accents.
In 2007, Harry Kümel revealed in an Interview that initially, Delphine Seyrig, already being a well-renowned icon of sophisticated European cinema, wasn't too eager to take the part of the Countess Bathory when he sent her the script. Seyrig's Boyfriend, famous French Director Alain Resnais, was a big fan of graphic novels and when he imagined Kümel's material and idea of the film to be something of a graphic novel, he enthusiastically convinced Seyrig to take the offer. Kümel also said that, at that time, he and his co-writers thought Seyrig's consent was "too good to be true".