When production designer Stuart Craig was brought aboard to bring the story of Harry Potter and his adventures to the movies screen, he went to the source -- author J.K. Rowling -- with a list of questions about Hogwarts castle and its surroundings -- the Forbidden Forest,, the Black Lake, and even the Whomping Willow. Immediately Rowling drew him a map that illustrated how the castle was situated, where the Quidditch pitch was located, and how Hogwarts students made their way from the Hogwarts train station to the school. Craig considered that map the ultimate authority and pinned it above his drawing table, where it stayed for ten years of filming.