Locations in Fallout Shelter are usually references to other Fallout games or appear only in Fallout Shelter. Locations are only seen during random encounters or quests. If a dweller comes across a location while exploring, it will only say they went there, and the locations can't be seen.
The locations that can be explored and seen in Fallout Shelter all use a randomly generated internal layout. For example, two players will not explore the same Nuka-Cola plant.