The Pipe Maze is a series of underground tunnels that connect pipes all across the Mushroom World. However, this may be the kingdom The surface contains what appears to be an infinite field of pipes. In order to navigate the maze the gang splits apart into two teams, Mario and Sonic as one team and Shadow, Yoshi and Luigi as the other. The maze is dimly lit and eerie which keeps Luigi constantly anxious and scared, as well as adds to the "mysterious" feeling when Professor Frankley explains the Minus World. The "I Like Cereal" banana makes another appearance, exploding when it came into contact with the Wario Bros. and thus getting them flown outside, reinforcing the idea that it is omnipresent. In Super Mario Bros. Z, the only known entrance to the Minus World is a pipe hidden behind a brick wall, originally built to keep people out of the deadly Minus World. Due to Mecha Sonic's last-resort attempt to incinerate the heroes, a large section of the Pipe Maze was destroyed. The Minus World may have been ceased to exist because of this.
- The Pipe Maze is once a large "Mushroom Kingdom" from Super Mario Bros. 3, that Mario and Luigi saved several years ago. It is the seventh kingdom they saved. The Kingdom contained several different landscapes with mutiple pipes, such as plains, Islands, deserts etc. Its main residents are Piranha Plants, Munchers, Ptooies, and other carnivorous plants found in the Mushroom Kingdom. The kingdom was raided by Ludwig von Koopa.
- Jeff and Hal from the Bowser's Kingdom flash series make a cameo appearance in this area.