The kids in Louis Sachar's fiction book series about Wayside School (beginning with Sideways Stories from Wayside School) are students in a particularly high school.
Wayside school is built sideways, in a way: it's 30 stories high, with one classroom per story. There is, however, no 19th story--much like real life buildings without a 13th floor. One student wonders, if there's no 19th floor, why isn't the school 29 stories tall?
Are you confused yet? Not as confused as our typists seem to be: highschool is in fact a high probability typo on the Ballard list, appearing over 50 times in Ohiolink and 1200 times in Worldcat!
(Book cover image from Amazon.com)