The Arkham city portion of the game board is divided into a number of locations, which represent parts of the city. Locations are where much of the game action happens, as investigators move around and have encounters.
Each location belongs to a neighborhood, near to other thematically related locations. All of the locations in a neighborhood are connected by street areas, and the street areas for different neighborhoods are interconnected, allowing the investigators to move between them. The boards for the larger expansions such as Dunwich or Innsmouth also contain town regions made up of locations and grouped into neighborhoods.
Each location is marked with icons depicting the most common type of encounters at that location. Some locations, such as Arkham Asylum, have special icons denoting a guaranteed method of acquiring an item (for example, at Arkham Asylum investigators can recover their Sanity).
Locations also have a stability rating indicated by a green or red diamond: green locations are stable, and monsters and gates will not appear there automatically; red locations are unstable, and monsters or gates can appear in these locations as a result of an encounter or drawing certain cards. Unstable locations, while more risky, also give players the possibility of encountering an Ally, and Clue tokens often appear in unstable locations when Mythos cards are resolved.
During the Arkham Encounters phase any investigator in a location with no gate can draw a location card from the Encounter deck for that neighborhood and follow the instructions. They may instead choose to take the location's Special Encounter, if they meet its conditions, instead of drawing a location card.
Note: Some cards or instructions use the term "location" loosely. In game terminology it usually means a specific named location on some city board, excluding street areas and Other Worlds. However, in some cases it may mean your current location, which can include street areas and Other Worlds. See specific card descriptions for any clarifications.