World 7

World 7 is a name often given to the seventh world in a game: 
*World 7 of Super Mario Bros.
*World 7 of Super Mario Bros.: The Lost Levels.
*World 7 of Super Mario Bros. 2.
*Pipe Land, alternatively named World 7, of Super Mario Bros. 3.
*World 7 of New Super Mario Bros.
*World 7 of New Super Mario Bros. Wii.
*World 7 of Super Mario 3D Land.
*World 7 of Puzzle & Dragons: Super Mario Bros. Edition.
*World 7 of Dr. Mario World.