- For other uses, see Vault.
The Vault was a structural "bunker" that had been built by the United Federation of Planets.
It was a huge subterranean complex located four hundred feet underground which was mostly deserted, but was actually the nerve center of Starfleet Command. This "giant brain" was self-contained and had independent life support capable of sustaining two thousand people forever, if necessary. The day to day inhabitants of this facility were machines and only a few occassional maintenance crews (though generally almost no one) went to the Vault. Banks after banks of screens were located inside the structure which monitored the deployment of Starfleet forces and watched over the security status of all sectors within the Federation. Data dumps from every starbase in the explored galaxy arrived within the Vault, along with incoming telemetry from probes and sensors of what lies beyond known space.
The main mission rooms were replaced inside this complex with vasy arrays of tactical displays. Over a century ago, at the height of the conflict with the Romulan Star Empire, the Vault had been hollowed out of bedrock under the old Starfleet building. This was to ensure its impenetrability, secrecy and survival, if Earth ever came under direct attack. Despite no assault against Earth, potential threats against the Federation never ended; which meant the food synthesizers were always maintained and data flowed in a never-ending torrent. This was because Starfleet had to protect the peace and the Vault was design in case of war.
Only a few Starfleet officers were aware of the Vault's existence-with only three starship Captains possessing the clearance to enter the facility. In 2279, Captain James T. Kirk entered the Vault, though he personally hated the facility. (TOS novel: The Pandora Principle)
- Presumably, the Vault was constructed either by the United Earth government, Coalition of Planets or Earth Alliance in light of the ENT novels and canon information about that time period. Possibly, the 2100s' equivalent of the Starfleet Corps of Engineers had built it.