The Citadel is a nuclear missile defense system that will shoot down incoming intercontinental ballistic missiles targeted within its 2,000 coverage radius.

Build a Tracer nearby to detect cloaked EMP units before they can disable it.

Each defensive missile takes 150 metal, 7,500 energy and 90 seconds to build. It can hold up to 20 missiles at a time, but you may wish to manually reduce the stockpile limit so as not to waste resources.

‍