'The marauders' map'
as featured in the 'Harry Potter' series by J K Rowling.
In 'Harry Potter and the prisoner of Azkaban' — the third novel of J K Rowling's 'Harry Potter' series — Fred and George Weasley give 'The marauder's map' to Harry.
A magical document that reveals the whole of Hogwarts School of Witchcraft and Wizardry, the map includes every hallway, secret passage, and classroom. In addition, it also shows the exact location of every person within the castle and its grounds, even the ghosts.
On the front of the map is written: 'Messrs Moony, Wormtail, Padfoot and Prongs are proud to present the marauders' map'. Those are the names of the map's fictional creators: Remus Lupin, Peter Pettigrew, Sirius Black and Harry's father James Potter.
The map is opened by a touch from a wand, with the words 'I solemnly swear that I am up to no good'. Another wand tap and 'Mischief managed' returns the map to looking like a blank piece of parchment.