World B-3

World B-3 is the third level of World B in Super Mario Bros.: The Lost Levels and the eleventh secret level overall in said game. It is the only athletic level in the game where the time limit is 300 seconds instead of the usual 400.

Layout
This level consists of several scattered platforms with Koopa Paratroopas between them. After the first scale lift platforms are four lifts, two that drop and two that move horizontally, and above the second lift is a ? Block with a power-up. Past the first Super Spring are small platforms followed by pipes with Piranha Plants, and Bullet Bills will begin firing from the right after the second Super Spring. In the group of Brick Blocks ahead, the one on the right holds a power-up, though not in the Super Mario All-Stars version of the game. After another Super Spring and a scale lift are platforms with large gaps between them; in order to cross the first gap, the player has to time a jump off of a Koopa Paratroopa. After the platform with the Koopa Troopa is the Goal Pole.

In All-Stars, the uncommon green Super Springs are replaced with ordinary red Springboards.