World 4-4 (Super Mario Bros.)

World 4-4 is the fourth and final level of World 4 in Super Mario Bros. and the sixteenth level overall in said game.

Layout
The player starts at the top of stairs that end at lava pits. Ahead are two paths, and the player must chose the correct path in order to move forward; taking the top path will bring the player to the next hall, whereas taking the bottom path will bring the player back to the start of this puzzle. (In Super Mario All-Stars and Super Mario Bros. Deluxe, a chime indicating whether the player took the right or wrong path will sound.) In the next hall, the player has to jump up a set of platforms to reach the next puzzle, split between three paths. Taking the bottom path will lead to the fake Bowser, whereas taking either of the other two paths will bring the player back to the lava pits at the start of this hall. While moving along either of the paths, the fake Bowser will begin breathing fire at the player. The bridge the fake Bowser is on has a Fire-Bar placed on it and a Podoboo jumping up from underneath.

Super Mario Bros. Deluxe challenges
In Super Mario Bros. Deluxe, the player can collect five Red Coins, find a hidden Yoshi Egg, and get a medal based on their score. The Yoshi Egg is found in a Hidden Block directly to the left of the single block before the second puzzle, and the score to beat is 17000 (14000 in the Japanese version ). The Red Coin locations are:
 * Between two of the pillars of the top path in the first puzzle
 * Over the lava pit before the second puzzle, the player needs to do a corner jump to collect it
 * At the start of the middle path in the second puzzle
 * In the air before the fake Bowser, a Hidden Block is placed directly below it
 * In front of the fake Bowser

Trivia

 * This is the only castle level in Super Mario Bros. where there is a Fire-Bar on the boss bridge.