Over two scenes in the detective's office the map of Los Angeles becomes more prominent, eventually becoming legible when used as background to the Captain's pointed enquiries as to whether Laurel Gray will be marrying Dixon Steele:
There are two maps in the film. One is important to the plot, the other not at all. The first is given to Slaughter by a police officer who wants him to burgle a gangster's safe.
The map is then shown by Slaughter to the former safe-cracker (now pimp) with whom he will carry out the burglary:
The details of the map are either too feint or too distant to be readable, but it is anyway the idea of the map that counts for the story.
The other map is readable, and is presumably of Los Angeles (where the film is set and shot), but it serves only as establishing décor in an office where the gangster's takings (from prostitution, gambling etc.) are being added up:
This map can be seen in the background when Slaughter launches his one-man revenge attack at the climax of the film:
In explaining the details of the robbery the planner he goes from each point on the map to a photograph of the location, and every time there is a flashback to the moment the photograph was taken.
For more of the cameras from this sequence, see here.)
Danger: Diabolik features one of cinema's finest map sequences. The police inspector is working things out by marking areas on a map, but the film animates the spread of his marking rather than laboriously have him do it by hand. (You can see it fully animated here, about 4 miutes 30 seconds into the extract.)
The setting of the action is ostensibly England, but the shooting was in Italy and many of the incidental accoutrements are distinctly continental. Englishness is denoted by cars like the E-type Jaguar and newspapers like the News of the World. The map being studied by the inspector has English words on it, but is in fact of Los Angeles: