Vault 76

Vault 76 is one of the Vault-Tec vaults shown on the computer in the Citadel. The Vault-Tec Terminal in the Citadel lists Vault 76 as a "control" vault, with 500 occupants. The vault was designed to open after 20 years. It was among the seventeen total control vaults, meaning it functioned precisely according to occupants' expectations. It is also mentioned in one of the Alien Captive Recordings recorded by Giles Wolstencroft a vault-tec official who was abducted while overlooking the vault's construction site.

Appearances
Despite being mentioned in Fallout 3 and in Mothership Zeta (add-on), Vault 76 does not appear in the actual game.