A moving tapestry of Barnabas the Barmy, depicting his foolish attempt to train trolls for the ballet, hangs in the halls of Hogwarts Castle, opposite the entrance to the Room of Requirement. That stretch of corridor has a window on one end and a man-sized vase at the other. There's a statue of Lachlan the Lanky between the stairs and the Fat Lady's portrait. Another corridor on the seventh floor is the location of the gargoyle which guards the entrance to the Headmistress's office. During classes, try to keep the Hallway quite...