A hidden area that acts as a kind of freeway, connecting many worlds to one place.
In Super Mario Brothers, the zone was just a sectioned off area of sewer levels, containing pipes to different levels.
File:Mario bros3world 9.jpg
Warp Zone in SMB3.
In Super Mario Brothers 3, the zone was actually an island and could only be accessed via Warp Whistle. Fans sometimes refer to the area as ‘World 9’.