Grand Staircase

The Grand Staircase is a massive structure in Hogwarts which is located in Grand Staircase Tower. It is mainly used to access each floor in the castle, including the basement and dungeons. There are hundreds of portraits on the walls of the Grand Staircase Tower. Some of the portraits reveal hidden/secret passageways within the school. The multiple staircases move from one platform to another that ends at the seventh floor. The moving staircases came from Rowena Ravenclaw's idea who is one of the founders of Hogwarts. It is also called the Marble Staircase. \