|World location||World 1|
|Previous level||World 1-3|
|Next level||World 1-4|
|Game(s)||New Super Mario Bros.|
World 1-Fortress is a tower level with gray walls, and ominous music playing in the background.
At the very start, there is a Dry Bones and a platform which rises up and down. Right after this, there are five pairs of walls which will crush Mario if he goes between them as they are closing. On top of the fifth pair, there is another Dry Bones. There are also numerous coins in the area. After this, there are several walls go up and down one by one, so Mario has to run below them. Then there is another Dry Bones, and the first Star Coin in the level. There are even more walls after this, but this time Mario has to jump on top of them to proceed. After this, Mario can enter a room with shifting walls and the second star coin. There is a secret exit here which can only be reached if Mario is Shell Mario. In the room, there is a gap that never closes. Mario has to enter it and jump upwards, where he will find a 1-Up Mushroom. He will then have to jump onto five more blocks, and start using the Shell Dash. Then, after destroying all the blocks, Mario has to enter the Warp Pipe. Then, he will fall to the right after exiting. Mario must jump onto a block to obtain another 1-Up. Then, he will unlock the Warp Cannon which will take him to World 5. There is then the third Star Coin, which can be reached by jumping on top of the walls and avoiding the spikes. However, in order to get back to the main level, Mario needs to avoid being crushed by the walls in the next room. If Mario chooses to go the normal way, then he will either rocket up the tower with a warp pipe or wall jump up it. After this, there is a warp pipe which will shoot Mario up the tower, but he can be crushed by the walls here. There are also two Super Dry Bones after this, and then the exit to the Bowser Jr. battle.
In the first Bowser Jr. battle of the game, Bowser Jr. will run around the tower. Once he is hit three times, he will be defeated and he will drag Princess Peach to World 1-Castle.
- Star Coin 1:
- Star Coin 2:
- Star Coin 3: