Wow!
This film is up there with "Hiroshima, mon amour", "Last Year at Marienbad", "Muriel", and "La guerre est finie", (not to mention the short "Night and Fog", which so many people all over the world have seen without necessarily making the connection that it was directed by the same man who made "Marienbad"!) It is part of the same great period. Amazingly, it is never shown and is practically unobtainable. It may be Resnais's most difficult film, certainly no easier than "Marienbad". I can't say it is the most beautiful to look at, although the worse than mediocre visual quality of the video I saw did not make it easy to make a fair assessment. It is, however, so complex that you really need multiple viewings to get a handle on it. As for figuring it out completely, that I am not sure about.
Anyway, this is an amazing work of art.