World 1

World One is always the first world in a Mario game. It is usually easy, and put there to help the player learn how to play to the game. Various World Ones include:

World 1 (SMB) - Was World One In Super Mario Bros.

World 1 (SMB2) - Was World One In Super Mario Bros 2

Grass Land - Was World One In Super Mario Bros. 3

World 1 (NSMB) - Was World One In New Super Mario Bros

World 1 (YI) - Was World One In Yoshis Island

Yoshi's Island (place)- Was World One in Super Mario World

World 1 (SMB: TLL) Was World One in Super Mario Bros.: The Lost Levels