Necropolis

The Necropolis, a town built upon the charred remains of Bakersfield, is the grim aftermath of Vault 12; it is best described by Killian Darkwater: "The climate ain't good, rain or shine." The true purpose of that vault was to keep the doors open regardless of the conditions, which spelled disaster to anyone attempting to seek relief from the radiated aftermath of the Great War. The residents of the Necropolis were ghouls, individuals ravaged by the effects of radiation after the Great War. To most of post-War California's residents Necropolis was a haunted city, at times a myth used to frighten children, a "city of cannibals" inhabited by brain-eating ghouls.

Inhabitants
The ghoul population was divided into three groups:

The surface dwellers were what could be called the public face of Necropolis, as they were by far the most numerous of the three groups, and controlled most of the city's surface. They were typically the first thing outsiders encountered in Necropolis, and were likely the cause of the aformentioned rumours surrounding the City of the Dead. Their operations were based out of the Hall of the Dead, where their leader Set did his business. Paranoid and intolerant of outsiders and non-ghouls, the surface dwellers were often violent, attacking strangers on sight and harboring a particularly deep hatred of super mutants. This was most likely due to the super mutant garrison newly established around Necropolis' important Watershed. Though Talius mentions heated resistance to the super mutant presence in the city by Set's surface dwellers, by the time the Vault Dweller arrives there appears to be a sort of stalemate between the two groups, though Set does not hesitate in employing the outsider to eliminate the super mutants garrison.

The Glowing Ones were heavily irradiated ghouls who lived in the old Vault 12, shunned by even their own kind, who disliked the other ghouls as much as the normal humans.

The so-called underground ghouls, who were forced to live in the city's sewers, though they were by far the most peaceful of Necropolis' residents and were much more tolerant of outsiders than either of the other groups.

Eventually, the town was taken over by a several of the Master's super mutants. An individual called the Vault Dweller killed the mutant invaders, but unfortunately Ian, one of his friends, was killed. The town was eventually raided by a larger super mutant force, and many of the ghouls were killed. Most ghouls, however, managed to escape, leading to the Great Migration across the wastes to towns such as Gecko, Broken Hills and Reservation.

Appearances in games
Necropolis appeared only in the first Fallout game.

Inconsistencies
In Fallout 1, according to the Vault-Tec Vault Locations holodisk, Vault 12 was located in Bakersfield. However, while Necropolis lies to the Northeast of Los Angeles, the actual city of Bakersfield is not far to the Southwest of the Lost Hills bunker (which is not a Vault, but a military bunker, as suggested by Captain Maxson's log). The location of Necropolis roughly matches the town of Barstow. It can be assumed that while Necropolis was initially placed where Bakersfield is, the locations were moved at a later date to spread them out better along the map.