Fallout 4 concept art
Vault 17 is one of the Vault-Tec vaults. The vault's original purpose in the vault experiment is unknown. The vault is located somewhere in New California, however, the exact location is also unknown.
Lillian Marie Bowen, Becky and Jimmy are the only known inhabitants of Vault 17. They lived in the Vault until Lily was 75 years old, at which time she was captured by the Master's Army and turned into a nightkin.