Fortress of Winds

The Fortress of Winds is a location in The Minish Cap. It is large complex that was once inhabited by the Wind Tribe; however, they abandoned it and traveled to the Cloud Tops, making it serve as the third dungeon in the game. Instead of receiving the Wind Element from this dungeon, which the Wind Tribe took with them to the skies, the Ocarina of Wind is obtained, allowing Link to fly to any uncovered Wind Crest in Hyrule.

Themes and Navigation
The dungeon is effectively a three-dimensional maze, as it has three floors and rooms on the same floor are frequently not directly connected, moreso than in most other dungeons, and thus routes from one part of the dungeon to another tend to involve both horizontal travel through part of a given floor and vertical travel between floors via ladders or holes that Link must fall through. The main item is the Mole Mitts, which are instrumental in navigating the dungeon, as much of it is filled with earth that must be tunneled through to proceed.

Unusually for this game, the Fortress of Winds has a post-boss area. After defeating Mazaal, Link ascends to the roof of the dungeon, where he finds the Ocarina of Wind and a plaque telling of the Wind Tribe's departure to the Cloud Tops.

Trivia

 * Mazaal, the dungeon's boss was originally designed to repel intruders from the fortress. And apparently, it has done a good job, since there are no living enemies (that is except for the Keeses) to be found whatsoever.
 * Despite its name, the Fortress of Winds is not wind-themed whatsoever. The name likely refers to the Wind Tribe who inhabited the fortress previously.