Brooklyn

Brooklyn is a borough of the greater city of New York and is located in the United States of America.

One of its first mentions in a game is in Mario's Time Machine, in which upon being asked if he was from Italy (due to his accent) by an imperial ruler in China, Mario says that he is from Brooklyn, New York. Of course, granted the time period, the feudal lord didn't know what Brooklyn was.

According to Mario is Missing! (both the original PC version and console instruction booklets) and the Super Mario 64 Player's Guide, in addition to the DIC cartoon shows and Nintendo Comics System, the Mario Brothers are from Brooklyn.

The Super Mario Bros. Super Show!
In The Super Mario Bros. Super Show!, it is shown that Mario and Luigi ended up in the Mushroom Kingdom by getting sucked down a Warp Pipe connected to the drain of bathtub that they were unclogging.

In the cartoon episodes, Mario and Luigi often make references about their former lives in Brooklyn, or lament on how they wish to return home. The live action segments all took place at the Mario Brothers Plumbing shop in Brooklyn.

In the episode "Brooklyn Bound", Mario and Luigi meet up with Salvador Drainado, a fellow Brooklyn plumber who had been lost in Mushroom Kingdom for thirteen years. However, Salvador Drainado had discovered a one-way drainpipe to back to Brooklyn, which could only be used once. With Mario and Luigi's help, Salvador Drainado was able to reach the pipe, and offered Mario and Luigi to come along. Mario and Luigi almost go along with Salvador Drainado, but decide to stay behind in the end to save Princess Toadstool and Toad from Koopa Khan and the Koopa Pack.

Brooklyn is also featured in the episode "Plummers Academy". In an extended flashback sequence, Mario tells the story of how he and Luigi became plumbers after being flunked by Sergeant Kooperman at the Brooklyn Plumbers Academy.

In the episode "Flatbush Koopa", a Warp Pipe leading to Brooklyn is discovered, and Mario and Luigi, having defeated King Koopa, get to return home. When they get there, they are surprised to see that King Koopa is slowly turning the city into "Kooplyn", as revenge against the Mario Bros. for ruining all of his evil plots. Although they manage to foil King Koopa and lead him back to the Mushroom Kingdom, Mario blows up the pipe with a Bob-omb, if only so that King Koopa can't return to Brooklyn. By blowing up the pipe, Mario and Luigi are forced to stay in the Mushroom Kingdom.

The Adventures of Super Mario Bros. 3
In The Adventures of Super Mario Bros. 3, more Warp Pipes leading to the real world had been discovered, making access to Brooklyn much more convenient.

In the episode "Toddler Terrors of Time Travel", Bowser and Kooky try to go back in time to stop the Mario Bros. from going down the drainpipe in Brooklyn, but their plan screws up when the Time Tube turns them, along with Mario, Luigi and Toad into babies.

In "Misadventures in Babysitting", Mario and Luigi accidentally warp into a Brooklyn home, and get suckered into babysitting a brat named Junior, who warps himself to the Mushroom Kingdom in a game of hide and seek.

In "Recycled Koopa", the Koopalings dump their garbage down a Warp Pipe to Brooklyn. As a result, the garbage mutates the people there into Koopa Zombies. Mario and Luigi do what they can to clean up the garbage before the entire city gets contaminated.

Club Nintendo
The story of the Club Nintendo comic "Super Mario: Im Rausch Der Geschwindigkeit" takes place in Brooklyn, where there is a fictional speed limit of 80 "dinosaurpower" Mario is overstepping.

The Nintendo Skyscraper, which appears in the story "Super Mario in Die Nacht des Grauens", is also located "in the heart of Brooklyn".

Super Mario Bros. (film)
In the Super Mario Bros movie, Mario Mario and Luigi Mario live in Brooklyn, where they run the Mario Bros. Plumbing Service. The bulk of the film takes place in Dinohattan an alternate-universe version of New York City in a world where humans evolved from dinosaurs.

Trivia

 * Additionally, the manual to Sim City says that the Mario Bros. live in Brooklyn, stating that it's odd that Bowser is looking for them in Tokyo rather than there.
 * Brooklyn is also home to the well-known Brooklyn Bridge, which can be seen all the way from Mario Brothers Plumbing. The bridge itself was also seen in several cartoon episodes and was mentioned a few times in the live-action segments of The Super Mario Bros. Super Show!.
 * Since Flatbush is the only neighborhood of Brooklyn prominently featured, it can be assumed that the Mario Bros. grew up there.