Mario World

Mario World, called Mario's world in Super Mario RPG: Legend of the Seven Stars, refers to the area that the Smithy Gang attempted to conquer. After Mario rescued Princess Toadstool from King Bowser, a giant sword known as Exor plunged into Bowser's Keep and sent the three flying in separate directions from the impact. To locate the princess and investigate the cause of the sword's appearance, Mario begins to travel the world, eventually finding the cloud Mallow and the mysterious self-aware doll Geno. Geno reveals that he is actually an emissary of the Star Road, which was shattered by Exor shortly before crashing into Bowser's Keep. The Star Road grants the wishes of the world, which take the form of small shooting stars that fall on the mystical Star Hill. Smithy sent his crew to collect the fallen Star Pieces, fragments of Star Road, to prevent it from ever being restored and fulfill his own dream of filling the world with weapons. Together, the three continue to work their way around Mario World, eventually recruiting Bowser and Toadstool, and collect the seven Star Pieces along the way. After defeating Smithy, the full seven star pieces restore Star Road, Exor disappears, and peace returns to Mario World.

Trivia

 * The term "Mario World" was first used in the instruction booklet of the console ports of Mario is Missing! However, in that context, it may instead refer to the direct counterpart of "the real world," which was a distinguishing concept utilized in contemporary cartoon and film media.
 * The name is also reused in Mario Tennis: Power Tour, though in that instance it appears to apply to the small floating area in the clouds which houses the Peach Airport and Peach Dome.
 * The name is used again in Mario Golf: World Tour as a classification of nine-hole golf courses with elements from the Mario universe where Character Costume challenges take place.