Vault 8
From FOnline: 2238 Wiki
Vault 8 was one of the pre-war Vaults designed to save its dwellers from nuclear bombs and radiation. Once everything outside was safe, the Vault opened and the dwellers came out, founding Vault City. The Vault is located in the inner part of the city, so you'll have to be a citizen to be able to enter it.
The Vault is fully functional and is now only used for medical purposes, which turns Vault City into the community that has one of the best medical facilities in the Wasteland, along with the Enclave and the Brotherhood of Steel. The Vault has three levels (two are underground).
Interests
The Vault hosts Dr. Troy. Most of the doctors of the Wasteland are from the Vault City faction, thanks to Dr. Troy.