The Avengers: Earth's Mightiest Heroes Wiki
Negative Zone

The Negative Zone is parallel universe made completely of anti-matter where cosmic beings dwell.

It's used by Tony Stark, Reed Richards and Hank Pym to place recaptured supervillains to the new prison, they built in the Negatize Zone, after the Breakout incident.

The only entrance and exit is through the portal that leads to the Negative Zone where the prison stands. It's guarded by elite Mandoids somewhere inside the Baxter Building.

The Negative Zone is home to creatures that serve Annihulus. Galactus was banished there in order to save Earth and so that he could feast on the endless anti-matter.