Shutter Island...... what prison was this filmed at?

Not all prisons in films are not always filmed in actual prisons.

here is the filming locations for where it was filmed

http://www.imdb.com/title/tt1130884/locations

i haven't seen the film yet but hope this helps

1

They filmed a majority of the film on Ashecliffe, which is a real place.

A few of the scenes were shot on soundstages, like most of the hallucnation/dreams that DiCaprio has.

and last, the World War 2 scenes were shot in Vancouver.

Hope this helps....