Wind Fish's Egg

The Wind Fish's Egg, also simply referred to as the Egg, is the gigantic egg that sits on top of Mount Tamaranch in, and is said to be where the Wind Fish sleeps. To get to the egg, Link must climb up a fleet of stairs near Goponga Swamp, but he won't be able to open the way inside until he has collected all eight of the Siren Instruments. The egg is white with several pink spots and can be seen from many parts on the island. The egg is commonly seen in a beam of light surrounded by a cloudy ring.

Overview
After completing Eagle Tower, Marin can be found on a broken bridge on Tal Tal Heights as a result of a kidnapping. After rescuing her, the Owl reveals that she attempted to awake the Wind Fish by singing the Ballad of the Wind Fish in front of the egg.

The Wind Fish's Egg is the final dungeon in. Shortly after obtaining the final instrument, Link will be redirected to the egg. Link then plays the Ballad of the Wind Fish by using his ocarina along with the other instruments. When the song ends, part of the egg's shell suddenly cracks open and reveals an entrance, allowing Link to go inside. The design of the inside of the egg is very simple, lacking any decoration, making it rather mysterious.

The egg contains an endless maze similar to the recurring Lost Woods. To correctly navigate it, Link must follow a specific sequence of directions. However, this sequence is randomly set whenever a new game is made. To determine the correct sequence, Link must read a book titled "Dark Secrets And Mysteries Of Koholint" inside the library in Mabe Village. The book has very fine print that can only be read with the aid of a Magnifying Lens, so it is necessary to complete the game's Trading Sequence. However, it is still possible to successfully navigate the maze without reading the book or having the Magnifying Glass in Link's possession.

After successfully clearing the maze, Link will come upon a pit. By dropping down, he will encounter the final boss and the last of the Nightmares. Once they have been defeated, a stairway will appear and will lead Link to The Wind Fish's room, where the Owl and the Wind Fish await him.

Trivia

 * The concept for the world ending when a large egg breaks on top of a mountain, was an idea originally planned for A Link to the Past.