World 1-3 is the third level which appears in World 1 and New Super Mario Bros..
The location of this course is set in the sky. It features many mushrooms that Mario can walk across.
Layout
The first part of the level has a ? Block and a red Koopa. Shortly after this, there is a Spin Block which Mario can use to fly up to some other mushrooms. If the player chooses not to do this, then they will be faced with some Goombas. Numerous coins can be obtained if the player uses the Spin Block. Quite high up, there is a bouncy pink mushroom. If the player presses down while airborne, they can jump very high using this mushroom. The first Star Coin in the level can be gotten in this way. After this, there are several swaying orange mushrooms, and the player can fall off of them if they are not careful. Then, there is the second Star Coin in the level, which is on top of an orange mushroom near some blocks. Right after this is the Midway Point of the level, a red Koopa, and some more swaying orange mushrooms. The third star coin is found above the orange mushrooms. After all this, there is a Red Ring above even more orange mushrooms. These mushrooms rise up and down instead of swaying. Then there is another red Koopa, some more swaying orange mushrooms, and then comes the exit of the level.