In Amazing Spider-Man issue 535, Tony and Reed shows Peter the giant "Resthouse" for unregistered superheroes or villains. This "Resthouse" is in The Negative Zone.
The Annihilation storyline includes Annihilus of The Negative Zone made a remark of the 616 realm encroaching The Negative Zone or something to that effect. I am not sure if it was in the 4 issue mini-series of the Silver Surfer.
Perhaps there might be a tie in of some sorts.