Prison 42

During the Super-Hero Civil War, a group of heroes led by Iron Man, Mister Fantastic and Yellowjacket created a massive prison in the Negative Zone to house captured non-registering heroes as they waited for their trials. It was designated Negative Zone Prison Alpha but nicknamed "Fantasy Island" or "Wonderland" by inmates. Tony Stark himself named it "Project 42", as it had been the 42nd idea out of a hundred that he, Reed Richards and Hank Pym had created following the Stamford Disaster. There were portals to it planned for every single state so prisoners could be transported there by the different teams in the Fifty State Initiative- including one at Ryker's Island. It was very clean, with sanitation, but extremely heavily-guarded, including password-changes every ten minutes.