L'Année dernière à Marienbad was created out of an unusual collaboration between its writer Alain Robbe-Grillet and its director Alain Resnais. Robbe-Grillet described its basis: "Alain Resnais and I were able to collaborate only because we had seen the film in the same way from the start, and not just in the same general outlines but exactly, in the construction of the least detail as in its total architecture. What I wrote might have been what was already in [his] mind; what he added during the shooting was what I might have written. ...Paradoxically enough, and thanks to the perfect identity of our conceptions, we almost always worked separately."
Robbe-Grillet wrote a screenplay which was very detailed, specifying not only the décor and gestures but also the placement and movement of the camera and the sequencing of shots in the editing. Resnais filmed the script with great fidelity, making only limited alterations which seemed necessary. Robbe-Grillet was not present during the filming. When he saw the rough-cut, he said that he found the film just as he had intended it, while recognising how much Resnais had added to make it work on the screen and to fill out what was absent from the script. Robbe-Grillet then published his screenplay, illustrated by shots from the film, as a "ciné-roman" (ciné-novel).
Despite the close correspondence between the written and filmed works, numerous differences between them have been identified. Two notable examples are the choice of music in the film (Francis Seyrig's score introduces extensive use of a solo organ), and a scene near the end of the film in which the screenplay explicitly describes a rape, whereas the film substitutes a series of repeated bleached-out travelling shots moving towards the woman. In subsequent statements by the two authors of the film, it was partly acknowledged that they did not entirely share the same vision of it.
Filming took place over a period of ten weeks between September and November 1960. The locations used for most of the interiors and the gardens were the châteaux of Schleissheim, Nymphenburg and Amalienburg in and around Munich. Additional interior scenes were filmed in the Photosonore-Marignan-Simo studios in Paris. (No filming was done in the Czech spa town of Marienbad - and the film does not allow the viewer to know with certainty which, if any, scenes are supposed to be located there.) Filming was in black-and-white in Dyaliscope wide-screen.
Source : Wikipedia.