World 1-4 (Super Mario Bros.)

World 1-4 is the final course of World 1 in Super Mario Bros.. It is a castle course and the False Bowser found in the level is actually a Goomba.

Layout
Mario starts the level on an elevated area with block stairs heading downwards. There is a gap with lava and, right after it, a block. There are two lava gaps with a Firebar on the ground between them. There is also a Question Block with a Fire Flower in it. Past it, ta corridor with three Firebars must be crossed. Going through it, Mario reaches a room with three Firebars, two on the floor and one on the roof, along two Used Blocks. Mario, then, finds a room with six hidden Blocks, where the False Bowser's fireballs start to appear. He can use a gap to avoid the fireballs and then, Mario reaches the False Bowser on a bridge and a small platform moving from side to side above it. If Mario gets past the False Bowser using the platform or running under it and touches the Ax, the bridge collapses, causing the False Bowser to fall into the lava. A Mushroom Retainer is saved and Mario gains access to the World 2.