This paper examines the Paris Opera designed by Garnier, focusing specifically on those parts of the building that form the backdrop described by Leroux in "The Phantom of the Opera". These elements have also served as inspiration for various subsequent film adaptations. The study delves into Garnier's theories on theater/opera architecture and Leroux's literary creation, contrasting them with film adaptations of Leroux's work. These adaptations demonstrate the close relationship between literature, cinema, and architecture, generally adhering to the principles of the French architect. [ABSTRACT FROM AUTHOR]