Borg nexus

The Borg Nexus was a class of starbase that was employed by the Borg Collective to serve as their central communication and command networks within a sector of space.

Once operational, the Nexus produced a steady stream of Borg Drone's for use for the Collective. The Nexus was capable of producing Assembler and Collector craft for resource collection and the building of additional structures. To defend itself, the Borg Nexus possessed an array of energy weapons that allowed it to repel and destroy small assaults against itself.

(TNG video game: Armada II)