The Terwilliker Institute is the main location of The 5000 Fingers of Dr. T.
While Bart was having a nightmare about his piano teacher, Dr. Terwilliker, Bart's inside the institute to be forced (along with 499 boys for the 5000 fingers) to play to world's largest piano. It's the home of Dr. Terwilliker. No one can try escaping, because of so many guards (even roller skating siamese twins connected together by a beard) and so many search lights, and also the fences are eletrifying. Not only the Institute holds the world's largest piano, but it also holds rooms for Dr. Terwilliker, Bart's mother, cells for the 500 boys (even Bart) and dungeons for all of the world's non-piano playing musicians.