World 7-9 (Super Mario Bros. 3)
From the Super Mario Wiki
World 7-9 is the ninth main level and eleventh level overall of Pipe Land in Super Mario Bros. 3. The level becomes accessible upon completing World 7-7 or World 7-8 and its own completion unlocks World 7- 2.
The player starts at the bottom-left of a large maze of entangled pipes. To get through it, the player first needs to travel right until they come across Jump Blocks, with the middle of which containing a power-up. Jumping on the middle Jump Block, the player can jump up through a crack in the pipes, then the player needs to jump up two more cracks, avoiding a Para-Goomba in the process. The player then needs to grab and remove the Ice Blocks ahead, jump up the next crack, and travel to the right, using Wood Blocks as platforms across the gap. If the player moves off the pipes to the left, they can grab an Ice Block while falling and open up a path to some coins and a power-up. Continuing to the right, the player needs to fall below the Jump Blocks to the left and open up the path blocked by Ice Blocks. Dropping down afterward and moving right, the player will come across some ? Blocks, with the middle one holding a power-up, then the player needs to jump through the above crack and open up more blocked paths. Using Wood Blocks as platforms, the player will then need to open up more Ice Block paths before reaching the Warp Pipe that leads to the goal.