Growing up in Michigan every Teenager had to go to the ddfunct Eloise Insane Asylum.
Massive poor farm/sanatorium complex. All kinds of rumors about the horrors that occured there. It was first opened sometime in the late 1800's and there was something like 7,000 unmarked graves of people who died there.
The complex was massive dozen buildings connected by underground tunnels. You could definitely get lost in the tunnels. You'd find jars full of formaldehyde and some obscure floating giblets. Weird tools, stirrups, manoclles etc... occasionally youd hear movement or muffled voices. In all likelihood it was other dumbass kids.
Got chased off by security and cra ked my ribs running into a fence post. That was 3 days before a wrestling tournament so that sucked.
But there's a movie made about it. Its a pretty lousy B movie. I think its called eloise and is about dumb kids who go explore the closed hospital.