Realm of Memories

The is a stage in.

Entrance to the Realm
The FS: appears once FS: has been completed for the first time. Initially a FS: symbol embedded within the FS:, the activated symbol glows and becomes surrounded by sparkling lights. A beam then shoots into the sky from each Triforce piece, and the symbol raises to hover above the forest.

Like FS:, the FS: entrance has three color-coded doors. However, each door has a unique set of non-randomized levels. Initially, only the silver and golden doors are visible, and the silver door must be completed first.

Once the golden door has been completed, a shutter will open to reveal the third and final door. Placed between the sliver and golden doors, the hero's door bears a blue symbol resembling the Series:.

Themes and Navigation
The FS: is themed on different areas from, and , with the game's graphics changing to match the relevant art style. The levels are longer and slightly more difficult than the four other main NaN Stages, though they do not contain NaN Bosss.

Silver Door
The silver door levels are themed around. The first level is based on the ALttP: exterior. It includes puzzles requiring the use of the FS:, FS:, and NaN Bombs.

The second level is based on the ALttP: interior and largely consists of narrow passageways, often in combination with NaN Flying Tiles. It contains several NaN Cracked Blocks and includes puzzles requiring the FS: or NaN Bombs.

The third level is based on the ALttP: and features dense areas consisting of NaN Floor Spikess and NaN Holes. The FS: is heavily used to navigate across small moving NaN Platforms, and NaN Bombs are used to activate otherwise-unreachable NaN Crystal Switchs.

Golden Door
The golden door levels are themed around. The first level is based on the LA: with elements of LA: and LA:. It contains an abundance of NaN Cracked Blocks, NaN Locked Blocks, and NaN Holes, with puzzles requiring the FS:, FS:, and NaN Bombs.

The doorways of the LA: and LA:'s house have hidden chests containing large NaN Rupees.

The second level is based on LA: and consists of a mixture of small rooms and open areas. Most of the dungeon is scattered with NaN Cracked Floor Tiles and NaN Holes. It has multiple puzzles that can be solved using either the FS: or FS:.

The third level is based on LA:, gradually evolving into LA: and culminating at LA:. The mountainous area has several NaN Holes and steaming geysers that require the FS:. There are also areas accessed via NaN Eye Switchs and a FS: puzzle involving movable NaN Statues.

Hero's Door
The hero's door levels are themed around. The first level is based on the central TLoZ: with moderately-sized areas. Several NaN Cracked Blocks and NaN Eyegores require frequent use of NaN Bombs and the FS:, respectively. A series of islands also require the FS:.

The second level is based on the western TLoZ:, including the TLoZ: and TLoZ:. It heavily features spring tiles for navigation, though the FS: is also used to activate a FS:.

The third level is based on TLoZ: and consists of several rooms. Dense collections of NaN Holes often require the use of the FS: or FS: to solve puzzles.

Completion of the hero's door rewards the NaN Linkss with the FS:, allowing NaN Sword Beams to be fired when the FS: is full. This is reflected on the FS: with a FS: icon.

Trivia

 * All of the games referenced in the FS: actually take place after according to the link.