Located in an unidentified planet, Citopia prided itself for being a virtually impenetrable fortress, and it offered services of safekeeping to clients from other worlds.

The Guardians of the Galaxy bypassed Citopia's defenses, using as transport a mech modeled after Galactus' likeness to terrorize its citizens, and stole a Tachyon bubble that contained a baby universe as part of a deal with the Grandmaster.^[1]