The Dungeon Map is a recurring Dungeon Item in The Legend of Zelda series. Dungeon Maps are found in each dungeon of any game that features the Dungeon Map, and is basically its name; a map of the dungeon. It will show Link all the rooms in the dungeon and exactly how they connect to each other. Combined with the Compass, which shows all the Treasure Chest's location, tracking down everything there is to get in a dungeon becomes a piece of cake.
There are a few special appearances of the dungeon map that are different from the usual incarnation.
In the Snowpeak Ruins of Twilight Princess, the Dungeon Map is not found a chest like is the usual in Twilight Princess. Instead it is given to Link by Yeta, and is actually referred to as the Mansion Map. This map has no different uses then that of a normal map.
In Skyward Sword, not only does the Dungeon Map show the layout of the dungeon, but it also takes the use of the Compass, and also shows all the Treasure Chests and other notable stuff on the Map itself. This is the first game to do this; use the Dungeon Map to do both its and the Compass' job.