The movie, not the city.
Based on a play by Michael Frayn, the movie uses a shorter script. I haven't read the play so I don't know what was cut out, but the excisions were done neatly and probably with Frayn's guidance, because nothing seemed lost. Even though the movie is subtle when it deals with human relationships, it is also blunt, perhaps necessarily so, when it presents analogies between physical principles and psychological ones. Maybe the bluntness just irritated me because it reminded me of the lack of subtely in Bollywood films. Copenhagen is about the meeting between Niels Bohr and Werner Heisenberg that took place during the Second World War. The meeting was cut short by Bohr who angrily walked away. No one is entirely sure why, and you can easily guess which principle in physics Frayn will use to address that uncertainty.
Apart from the metaphors, there are other authorial seams showing as well, but the quality of the film as a whole made me want to forgive those flaws. At its conclusion, the story veers from the personal to the global. That Frayn makes the transition seem natural speaks to the richness of this movie.
Incidentally, I picked this film because a review of the Coens' The Man Who Wasn't There (1991) mentioned that a scene in that movie was a parody of the play Copenhagen. The movie was made in 1992. Lots of goodies are to be found at the PBS Copenhagen and BBC Copenhagen websites. And there's this follow up.