From DC by Night Wiki
Locations
Each chronicle is set in a city and its surrounding environs; although characters and events may take place elsewhere now and then, the bulk of the action is set within city limits. For locations outside of regular chronicle play that may be relevant to games, see the other links below.
The World of Darkness is made up of several different overlapping realms, with the mortal world of humans and vampires only one of many. The other realms below are unearthly places that may be visited by various supernatural creatures; few know much about them, and fewer still know enough of their secrets to travel there freely.