Citadel

  -Fortress-

  A fortress or strongly fortified building in or near a city, a place of refuge

-Defender-

A strong defender of a particular way of life or principle

  Intelligence

  -Ability to think and learn-

  The ability to learn facts & skills and apply them, especially when this ability is highly developed

-Secret information-

Information about secret plans or activities, especially those of foreign governments, the armed forces, business enemies, or criminals