In Zelda games, 'dungeon' often refers to a temple or temple-like structure, with rooms, keys, and a boss at the end. They are often mazes with many puzzles to solve, enemies to defeat, and sometimes even objects to collect. They are also good places to collect Rupees and Heart Pieces. Most dungeons are themed, and require you to use certain tools many times within the dungeon. A good example is the Water Temple in Ocarina of Time, which involves the use of the Zora Tunic, Iron Boots, and Longshot. Many times, you will acquire one or more of these tools in or shortly before entering the dungeon. At the end you will fight a boss. Usually you will need to fight the boss with the item you just got in the dungeon.