where was the series filmed?
Hollywood and Chicago are two of the locations.
Prison Break
The first three seasons of "Prison Break" were primarily filmed outside of Hollywood. The majority of the first season of the series was filmed on location in and around Chicago. 
when does prison break start its new season UNANSWERABLE how many seasons does this series have? UNANSWERABLE
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Prison Break [SEP] Filming
The first three seasons of "Prison Break" were primarily filmed outside of Hollywood. The majority of the first season of the series was filmed on location in and around Chicago. After it was closed down in 2002, Joliet Prison became the set of "Prison Break" in 2005, standing in as Fox River State Penitentiary on screen. Scenes set in Lincoln's cell, the infirmary, and the prison yard were all shot on location at the prison. Lincoln's cell was alleged to be the same one in which serial killer John Wayne Gacy was incarcerated, which at least one member of the production crew refused to enter, because it was alleged to be haunted.