Thanks, Sutinen, for the compliments. It's always a pleasure to read your comments.
In Opey's apocalyptic future, any building still standing is re-used for other purposes. In this case, the New Jersey State prison is used for an elementary school.
Drawing the landscape on this page was time-consuming pain, but since it was an establishing shot introducing Opey's school, I thought I might as well make it detailed as possible.