Fallout fans have posted a gallery of Vaults from the series, along with the location and secret purpose of each.
While the Vaults were publicly intended to save people in the event of a nuclear war, most were used for experiments. Vault 0 based in Cheyenne Mountain, was intended to monitor and control other Vaults. The smartest people in pre-War America were also cryogenically frozen here, and a robot army was intended to improve conditions in the wasteland.
Vaults 68 and 69 were intended to study extreme gender-imbalace. One had 99 men and only one woman, while the other had 99 women and only one man.
Vault 43 had a population of 20 men and 10 women and one panther, while Vault 77 was home to a single man and a crate of puppets.
Not all of these Vaults have actually appeared in Fallout games, with some being featured in the Fallout Bible, Penny Arcade's official comic, and Van Buren concept art. As noted, no one yet knows the purpose of Vault 111 from Fallout 4, but we do know that it opens after 200 years with only one survivor.
Fallout 4 launches on November 10th.