Bell towers

The Bell Towers are two square towers that rise over the main entrance to the Greenhouses of Hogwarts Castle. Between the two towers are a set of double wooden doors which lead along the first floor corridor, close to the Charms corridor. Inside the left Bell Tower is Filch's Office.

Behind the Scenes
In the first two films, the towers were quite short and had small "balcony-like areas" below the turrets at the top.

From the film adaptation of Harry Potter and the Prisoner of Azkaban onwards, they changed to being taller, thinner, having taller spires and no "balcony-like area."

In the Half-Blood Prince film, the Training Grounds Tower changed into another Bell Tower, but this one was slightly shorter.

Appearances

 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)