World 1 - Grass Land

The first world of Super Mario Bros. 3 features six levels, one set of Hammer Bros, two Toad houses and one Fortress. The doom ship which has taken over this land belongs to Larry Koopa. This land belongs to the Mushroom Kingdom. In the original SMB3 the King was turned into a dog, but in the re-release in Super Mario Allstars the King was instead turned into a Cobrat.

World 2 - Desert Hill

The second world also known in the re-release as Desert Land contains five levels, two sets of Boomerang Bros, a Fortress, three Toad houses, two special levels which were based in a Pyramid and a quicksand desert. There is also a special Fire Bro's level which can be unlocked by using a hammer on the rock at the upper right of the screen, beating the Fire Bros will then get you a warp whistle. There are certain enemies which are pretty much exclusive to this land to be seen here - such as the Angry sun and Fire snakes. Morton Koopa Jr is the Koopa Kid who has taken over this land, and is ultimately the boss of Desert Hill.

World 3 - Sea Side

Known in the original NES version as Ocean Side this world comprises; nine levels, two fortresses, two sets of Hammer Bros and five Toad houses. As you would imagine most of the levels are based underwater and common enemies include Blooper squids and Cheep-Cheeps. This land belongs to the Mushroom Kingdom and has been taken over by Wendy 'O Koopa.

World 4 - Big Island

The fourth world, also known as Giant Land is a world where everything is comparatively huge compared to Mario - even the ? and ! blocks are huge; the only exceptions to the new found giant status are Cheep-Cheeps, Spinys, Bullet Bills and Venus Fire Traps. The world contains six levels, two fortresses, two sets of Sledge Bros, four Toad houses and two Spade Panels. The Island if you look carefully on the map screen is actually shaped like a Koopa Troopa. This land belongs to the Mushroom World and has been taken over by Iggy Koopa (who is just regular sized). Another inhabitant of note here would be Madzilla who featured in Episode 9 of the Adventures of Super Mario Bros. 3 cartoon.

World 5 - The Sky

Known also as Sky Land, this is the fifth world of Super Mario Bros. 3 and comprises; nine levels, Three Hammer Bros, two Fortresses, three Toad Houses, a Sky Tower. Despite the name; some elements of the world are actually on the ground; The first three levels, two sets of Hammer Bros. and a Fortress - once these are beaten a player can use the Sky Tower which acts as a link between the ground element and Sky element. The Doom Ship which patrols the skies of this world can alternate between the ground and sky levels. This land is part of the Mushroom World and Roy Koopa controls it.

World 6 - Iced Land

Known with the slightly-alternative guise of Ice Land this world is the sixth in Super Mario Bros. 3 and consists of ten levels (the most in a single world in the whole game), three Hammer Bros, three Fortresses and two Toad houses. The Frozen lands treacherousness is complimented further by slippery ice and frozen lakes. This land has been taken over by Lemmy Koopa.

World 7 - Pipe Maze

Also known as Pipe World, the seventh and penultimate land in Super Mario Bros. 3 comprises of; nine levels, two Fortresses, three Toad Houses and two Special Piranha plant levels, the world is made up of various little islands linked together only by pipes (As the name may suggest). Ludwig Von Koopa is the ruler of this domain.

World 8 - Castle of Koopa

Dark Land also known as Castle of Koopa is the final World of Super Mario Bros. 3 and is ruled by King Bowser Koopa. This world consists of special levels such as Battle tanks, Air ships and Big tanks. Some of the further in areas of this world are completely shrouded in darkness and all you can see on the map screen is the little bit of light around Mario or Luigi.