The Marauder's Map is a magical document that reveals all of Hogwarts School of Witchcraft and Wizardry. Not only does it show every classroom, every hallway, and every corner of the castle, but it also shows every inch of the grounds, as well as all the secret passages that are hidden within its walls and the location of every person in the grounds, portrayed by a dot. It is also capable of accurately identifying each person, and is not fooled by animagi, Polyjuice Potions, or invisibility cloaks; even the Hogwarts ghosts are not exempt from this.
Harry Potter: A History of Magic at the New-York Historical Society is a celebration of the 20th anniversary of the publication of J. K. Rowling’s Harry Potter and the Sorcerer’s Stone. The exhibition captures the wizarding traditions of folklore and magic at the heart of the Harry Potter stories through centuries-old treasures including rare books, manuscripts, and magical objects from the collections of the British Library and New-York Historical Society—with original material from Harry Potter publisher Scholastic and J.K. Rowling’s own archives.