When it comes to making a spooky, atmospheric movie, it's all about location, location, location. Sure, sometimes it helps to set the action in familiar surroundings, to juxtapose them against whatever menace may be stalking our protagonists (i.e. Halloween). But for conjuring atmosphere, nothing beats a location that's already eerie - and few locations can out-creep a mysterious institution where more goes on than meets the eye.
Not only does such a setting bring a wealth of great, atmospheric locations to the film right away, but it also introduces twisty psychological elements like unreliable narrators and the inevitable last act reveals. Maybe the inmates were running the asylum the whole time, or maybe the person who we thought was investigating the institution from the outside was actually a patient - or maybe we're supposed to think they are, when really they're being held under false pretenses. There are lots of possibilities - and lots of movies that have explored them. Here are a few that you might have missed.