Shelbyville Zoo is a zoo in Shelbyville.
While Shelby and his gang were chasing Bart, Bart hid himself in a building with a sign reading "Danger: Tiger feeding area." There were twelve doors with roman numerals on them. Exit was only through door 7. All other rooms contained man-eating tigers."
Bart had no idea which door is 7th, but then he remembered at Rocky V, which was fifth, and found the right door.