Ouroboros

Oroborus is a town or village somewhere in the American southwest. It is where Hecate, the mad tribal "goddess" resides, as well as the Vipers, a group of raiders from the West who serve her.

Appearances in games
Oroborus did not appear nor was mentioned in any of the published games, but was to appear in the cancelled Fallout 3 project by Black Isle codenamed Van Buren. It is not certain if it will appear in any future Fallout game, but it is known that Bethesda received all Van Buren design documents from Interplay and might re-use some of the background from them.