Crystal Caves
Newer Super Mario Bros
Game(s) Newer Super Mario Bros. Wii
Newer Super Mario Bros. Wii Plus
World number D
Levels 5
Bosses None
Joined World None
Game Progression
Previous world (5) Freezeflame Glacier/Volcano (sec.)
Next world (6) Pumpkin Boneyard

Crystal Caves, or World D, is the fourth secret world of Newer Super Mario Bros. Wii. It is unlocked by completing the secret exit in World 5-8: Magma Iceburrow. This world has two exits. Completing the fortress will unlock a shortcut to World 6-3: Fog Cemetery. However, completing World D-A will unlock a shortcut to World 6-6: Cawcaw Treeway.


Crystal Caves is a violet cave that has many underground enemies.


Level number Level name Preview Description
D-1 Swooper Cellar Swooper cellar This level takes place in a cave with lots of Swoopers.
D-2 Toxic Wigglershift Toxic wigglershift
D-A Carapace Catacomb Carapace catacomb This takes place in a catacomb, as the name implies. This has Halloween as the goal pole area.
D-3 Spine Springs Spine springs
D-Fortress Toxic Fortress Maxresdefault (1) This level takes place in an underground fortress filled with poisoned water. Some of the floors/walls drop upon touch, so be careful. There is no boss in this level as with all of the lettered world fortresses.
D-15x15px The Red Switch Palace Red switch palace The Red Switch Palace can be accessed via the secret exit in 5-5. If the Palace is reached before Crystal Caves proper is unlocked, its world name on the map will read "???".

Other Buildings


  • The music of the levels is a remake of the underground theme from Yoshi's Island.