The post-apocalyptic wasteland of Fallout 4 is filled with remnants of pre-war society, none more iconic than the massive underground bunkers constructed by Vault-Tec. Scattered across the Commonwealth and its expansions, these subterranean structures offer unique environments, valuable rewards, and disturbing backstories. Exploring every vault allows players to uncovering hidden experiments and collect rare items that make survival much easier.
The Initial Commonwealth Underground Refuges
Your journey begins in the far northwestern area at Vault 111, located right near Sanctuary Hills where the main protagonist enters cryogenic stasis. Returning here later grants players access to the powerful Cryolator weapon locked inside the overseer office. Further east beneath the Malden Middle School lies Vault 75, which was designed as a dark testing ground disguised as a shelter for local school children.
Closer to the center of Boston, players can discover Vault 81, situated just west of the bustling Diamond City market area. This particular facility stands out because it is the only fully functioning and peaceful society left inside the region. Exploring its hidden laboratory wings allows you to recruit the companion Curie and acquire the Medicine Bobblehead.
Uncovering Urban and Coastal Facilities
Deep within the heart of urban Boston, players will discover Vault 114 by traversing the dangerous tunnels of Park Street Station. This site was initially intended to house wealthy local politicians but instead subjected them to cramped, impoverished conditions as a social experiment. You will visit this location during the main campaign while attempting to rescue the private investigator Nick Valentine.
Heading far down into the southern territory reveals Vault 95, positioned along the edge of the dangerous Glowing Sea region. This facility was populated with individuals suffering from substance addiction before Vault-Tec intentionally reintroduced hidden chemical supplies. Finding this location is essential for helping specific companions overcome their personal struggles and clear out high-level raiders.
Discovering Hidden Workshop and Island Spaces
For players who want to build their own custom underground base, Vault 88 can be uncovered underneath the Quincy Quarries area. This subterranean expansion is introduced through the Vault-Tec Workshop addon and is initially filled with wild creatures and debris. Clearing out the massive limestone chambers grants the player an enormous settlement area to construct a personal paradise.
Venturing completely away from the main map leads players to the distant Mount Desert Island featured in the Far Harbor expansion. Deep within the island territory lies Vault 118, which is hidden beneath the grand structure of the Cliff Edge Hotel. This unique bunker houses a group of wealthy individuals who successfully transferred their brains into mechanical robobrain bodies to escape the nuclear destruction.
