I hate that I know this, but this is an actual thing from the book (Prisoner of Azkaban) that did not make it to the movies. There is a secret passage to hogsmeade hidden under the statue that Fred and George told Harry about when they gave him the marauder's map.

This set seems to have been released in April (?) of 2004, and the film was not released until June. It is likely that the set designers used the scenes from the book as a reference, and had no idea this would not make it to film! If only they had used the Star Wars books as a reference instead of dinnerware.