The short answer is The Set: A Masterclass in TV Architecture While Prison Break did not film inside an active penitentiary (due to obvious security, safety, and logistical reasons), the production team achieved something arguably more impressive: they built a fully functional, working prison from scratch.
The sweeping aerial shots of the prison’s limestone walls, the imposing main gate, and the guard towers belong to the (also known as "Old Joliet Prison") in Joliet, Illinois. was prison break filmed in a real prison
For five seasons, audiences were glued to their screens as Michael Scofield meticulously unraveled his body tattoo to break his brother Lincoln Burrows out of death row. The claustrophobic hallways, the echoing cell blocks, and the ominous guard towers of Fox River State Penitentiary became as iconic as the characters themselves. The short answer is The Set: A Masterclass