Right by the main entrance to the University of Iowa Hospital is a building the University has abandoned, the Botany Plant House.
As far as I know it's the only building on campus that they've just abandoned. It's sad, because I really like greenhouses, and it would rule to have one I could go to on lunch hour. It's also sad they just left plants there to die.
i had a class in there two years ago. it was the last class ever held there. part of the building was condemned. the other part was a dessicated wasteland except for one small room. the mist room. where plants lived. now even that's gone and the banana tree died. i don't want to think of it.