World 1 (Super Mario Bros.)

World 1 in Super Mario Bros. is the first world in the game (there are eight in total). Naturally the four stages featured in World 1 are considered the easiest of the bunch. The four stages span four different environments including above the ground, the underground, on the tops of trees, and in Bowser's Castle.

Stages

 * World 1-1
 * World 1-2
 * World 1-3
 * World 1-4