World 5-Fortress 1

 1 is Sky Land's first fortress and either the third or fourth overall level, depending on the player's preference of progression. It is unlocked upon beating World 5-2, and, chronologically, comes after World 5-3. This level is optional, as the player has a choice to play either this level or World 5-3 in order to access the.

Layout
This level begins with Mario before a lava pit where a Lava Bubble jumps from. A Roto-disc also turns above this lava pit and the platform across the lava. Once Mario clears the lava, he immediately comes across a Thwomp. Past this Thwomp is four Brick Blocks. Breaking the middle two gives access for Raccoon Mario or Tanooki Mario to fly up a series of platforms that leads to a Red Warp Pipe. Below the Warp Pipe on a platform are two Brick Blocks and a ? Block, which produces a Super Leaf. The Red Warp Pipe leads to a secret area with coins in the shape of an arrow pointing up. Mario can fly up to hit three Hidden Blocks, all which spawn a 1-Up Mushroom. Mario then has access to another Red Warp Pipe which drops him back to the regular area. Before this Warp Pipe, had Mario chosen to not go for the secret room, is a staircase with two Roto-discs that lead up to another Thwomp. This Thwomp is between two Brick Blocks. The left one produces a Super Mushroom or a Super Leaf. Past this Thwomp are two more Roto-discs--one on the, ceiling the other on the floor--spinning simultaneously. A staircase to the right leads Mario down where the secret room's exit pipe leads to. A Boo is next to the Warp Pipe, and a Roto-disc situated under a gap in the wall circles around a Thwomp. Mario must jump on to the Roto-disc's middle orb to wait and bypass the Thwomp. Mario then encounters another Thwomp, whose landing blocks are a two gray block above a Roto-disc's orb. Past this Thwomp is a pit of lava. Across this lava pit is a platform where Mario will come across two more pits of lava. A Thwomp's landing blocks are in between the pits. Past this section is a staircase that leads up to the Warp Door to fight Boom Boom.

Enemies

 * Lava Bubble
 * Roto-discs
 * Thwomps
 * Boo
 * Boom Boom (boss)

Level Statistics

 * Power-ups: 2 (Super Mushrooms or Super Leaves)
 * 1-Up Mushrooms: 3
 * Secret areas: 1