One of the most famous, if not the most famous, prison in film history, must be the Shawshank State Prison. In the original story by Stephen King, the prison is located in Maine. Actual production took place in Ohio. Mansfield Reformatory, or Ohio State Reformatory (100 Reformatory Road), was used for the film, This prison was build in 1886 and when the film was made, they were about to destroy this historic building.
Most of the prison is still intact and open for visitors. Some of the original film location became a new (real) prison.