World 3-1 (Super Mario Bros. 2)
World 3-1 starts in a small area, where the only obstacle is a waterfall. Across the waterfall is the door to the next area, where the player has to jump on a vertical arrangement of clouds toward the top of a larger waterfall. Once at the top could, the player has to ride a Pidgit's carpet into the sky while dodging Beezos; they will soon come across the beanstalk to get to the next area. At the bottom of the waterfall is a door that leads to a cave. Here, the player can access a hidden Subspace Warp to World 5.
The right side of the area is populated by Shyguys and Pansers, with the door to the boss room and Red Birdo at the end. The area to the left is a shortcut that can take the player directly to the boss room, and can only be reached by Power Squat Jumping across the gap. Depending on the character, this may require the use of a Mushroom Block; when thrown to the left from high enough, it will 'land' on one of the smaller clouds and provide a platform to make crossing somewhat easier.