I was talking about this with a friend the other day, and I came up with this:
Basically the idea is that the series is set in a prison should as Alcatraz. I know it could be similar to Asylum but there would be no religion or nuns involved, or mental illness. It could be based around a group of prisoners plotting escapes, with one main character.
Also, there could be the idea of this:
American Horror Story: Theme Park
An abandoned Theme Park is restored and opened for a summer, after 30 years of being isolated and empty. The idea would be that the reason the park was closed originally was a string of gruesome murders and disappearances that caused visitor numbers to drop.