Flagstaff

Flagstaff is a mentioned only location.

Background
Before the Great War, Flagstaff was the first city in a series of carjackings committed by "Shanghai Sally" who was an alleged Chinese spy on the run from law enforcement. In 2255, the ruins of the city were taken over by Caesar's Legion, who christened it as their new capital.

Appearances
Flagstaff is mentioned in the Fallout: New Vegas Official Game Guide and

Behind the scenes
Flagstaff is a real world city in Arizona.