Null Void (Classic)

The Null Void is an alternate dimension created by the Galvan as a penal colony. It is filled with what look like never-ending floating rocks. Null Guardians are the guards of this prison dimension.

The realm is normally accessed by a Null Void Projector. Max is a known Null Void holder. He and his former partner, Phil, have owned one and trapped thousands of aliens in it while in their Plumber years. If a projector is broken and someone tries to access it, it self destructs immediately, with the power of a hand grenade. It is possible to release aliens within the realm.

Later in Alien Force, it is discovered that settlers live there as well the descendants of criminals.

In Alien Force, D'Void seized control over the Null Void and attempted to break through into Ben's dimension by means of a kormite powered-drill, but was defeated by Ben, Max, Helen, Pierce, Manny and some other aliens.

Fusion Fall
In the Game, players begin at the Null Void for Basic Training. There is a plumber training camp there along with Ben and the Rust Bucket III.

The Null Void background in the character selecter is a gitch for when a player moves up a level to the Zoo or Mt. Neverest it would stay like that until the players move to Sector V, after training.

Trivia

 * The Null Void seemed to be a horrifying/unpopular place, for example: Kevin was scared and horrified of going in there (or threatened to go there), Ben claiming that being in the Null Void is worse than prison, Argit hesitating to go there, even Vilgax had an eye twitch by just mentioning it, calling it accursed.
 * The Null Void is similar to the Phantom Zone, an intergalactic prison in the Superman universe that keeps dangerous criminals, such as General Zod.
 * For some reason, the Null Void is purple in the Original Series but red in Alien Force.