Citadel (The Secret in Vault 13)

The Citadel was a building on a planet conquered by the Fleet from which they planned their military operations.

It was situated in the Blasted Plains. The Citadel was a twelve-kilometre-high tower made of iridanium steel. It was protected from all weapons and from the tropospheric winds by force fields.

The Citadel housed supercomputers containing the knowledge of 10,000 star systems. (PROSE: The Secret in Vault 13)