World 5-4 (Super Mario Bros.: The Lost Levels)
From the Super Mario Wiki, the Mario encyclopedia
World 5-4 is filled with many large lava pits, Lava Bubbles, and Fire Bars. The first lift will fall when the player lands on it, which is followed by a narrow platform then a Fire Bar. The Brick Block between the three Fire Bars ahead contains a power-up. After two pillars and a Fire Bar, the room splits into an upper and lower path with a Lava Bubble jumping between them; the lower path has two lifts that fall under the player's weight and the upper path has Coins. The paths rejoin at a Fire Bar, after which are five small platforms with Fire Bubbles jumping between them. Next is another split path, with Fire Bars placed in the platform between them. Afterward are small platforms with both a small and a large Fire Bar and Lava Bubbles. Next is a long platform which the Fake Bowser ahead will begin breathing fire, followed by split platforms with Fire Bars before the fight with the Fake Bowser, which has a Lava Bubble jump from below the bridge and a moving platform above.