World 3-9 (Super Mario Bros. 3)
From the Super Mario Wiki
This level is composed of two parts, a normal one, and an underwater one. The player starts in the normal area, on two Semisolid Platforms, with a Koopa Paratroopa near them. Next is a large row of Brick Blocks with a Para-Goomba on top, and a Turtle Cannon below them. One of these Brick Blocks contains a power-up. Shortly afterwards, there are some Bob-ombs, Turtle Cannons and ? Blocks, if the player is Raccoon Mario or Luigi, they can go under the Wood Blocks, break the wall of Brick Blocks and enter a Warp Pipe which leads to the left side of the underwater area.
After this pipe, there are some Ice Blocks, alongside three Jump Blocks, with one containing another power-up. There is also another Bob-omb after this, as well as more Wood Blocks, Ice Blocks and a Koopa Troopa. After this, there is another Koopa Paratroopa, and a Warp Pipe leading to the right side of the underwater area.