Batchelor Middle School in Bloomington, Indiana, USA.
Ironically, there were very few walls inside. Classrooms were separated by accordion dividers which could be pulled back to connect three classrooms into one big classroom. There were no back walls to these classrooms, just a huge opening at the back. I'm told that's been changed in a renovation.
I used to fly in helicopters for a living (now just work on them) and we would occasionally make "ferry flights," flying an aircraft to some other area of the country. The pilots and I would regularly play "school or prison" and in some places it was reeeeeeally difficult to tell and required a Google Maps check.