World 2 (Super Mario Bros.)

World 2 is the second level of Super Mario Bros..

World 2-1
World 2-1 takes place above ground. It can be accessed by beating World 1-4 or by using the Warp Zone in World 1-2.

World 2-2
World 2-2 takes place underwater.

World 2-3
World 2-3 takes place above ground.

World 2-4
World 2-4 takes place in a Castle.