Hogwarts Staircases

What makes the stairs at Hogwarts so special is their "tendency to move" (Percy Weasley). It is because of this movement that Harry, Ron and Hermione ended up in the forbidden passageway in Harry Potter and the Sorcerer's Stone.

There are said to be 142 staircases in the seven floors of Hogwarts, most of which are located within one tower.