World 1-1 (Super Mario Bros.)

World 1-1 is the first level of World 1 in Super Mario Bros. The first screen of the level is also the game's title screen when starting it up. It contains the basics of the Super Mario Bros. game, getting the player ready for the journey ahead. The level consists of Magic Mushrooms, standard enemies such as Little Goombas and Koopa Troopas, a lot of coins, a hidden secret bonus area that allows the player to skip most of the level, Fire Flowers, pits, and a flagpole at the end. According to Shigeru Miyamoto, World 1-1 was one of the later levels created, due to the "fun" courses created first being more suited for late game, where players were more familiar with how Super Mario Bros. works. Like all levels in Super Mario Bros., it returns in Super Mario Bros. 35, where it is known as Course 1-1.

Layout
This level starts out on a flat, open path. As Mario or Luigi moves forward, a Little Goomba appears and starts walking towards them. They then reach the first ? of the game, and afterward the six block triangle formation of ?s and regular bricks (with a Magic Mushroom inside the left block). A set of Pipes can be found, with Little Goombas located in between them. The final pipe among the set leads to a bonus area of coins and can be entered to bypass much of the level. After that, assuming the pipe was not taken, there is a hidden 1 up Mushroom block and a pit followed by another ? containing an item, possibly a Magic Mushroom or Fire Flower, depending on the their form. Additionally, Little Goombas start falling down from a long row of blocks above. There is a brick down below contains ten coins that the plumbers can retrieve by jumping repeatedly underneath the brick. There are two bricks after that; the second one contains a Starman. Then there is a ? triangle formation. The top block contains a Fire Flower (or a Magic Mushroom if Mario is small). A Koopa Troopa and more Little Goombas appear. Bricks and ?s can be found, followed by a pyramid-like set of Hard Blocks with a gap in the middle. After that is another pyramid-like set of blocks, this time with a pit in the middle. Just following is another pipe that cannot be entered (which is the exit from the bonus area mentioned earlier), followed by two Little Goombas and four blocks in a row (three bricks and a coin-holding ?). Afterwards is another inaccessible pipe, the ending staircase for the level, and the flagpole, which is reused in all underground and underwater stages in the game.

Super Mario Bros. Deluxe challenges
In Super Mario Bros. Deluxe, Mario or Luigi can collect five Red Coins, find a hidden Yoshi Egg, and get a medal based on their score. The Yoshi Egg is found in a Hidden Block within the first set of pyramid-like steps, and the score to beat is 32000 (26000 in the Japanese version ). The Red Coin locations are:
 * On the row of blocks at the start of the level.
 * In the first Ten-Coin Block after the second pit. The player needs to collect all the coins first before the Red Coin appears.
 * In the third ? soon after the second Red Coin.
 * On top of the bricks soon after the third Red Coin. The player needs to use the single brick as a platform.
 * In the final ? of the level.

Recreations in later media
Due to its notability, the level has been re-created in many games and media.
 * Super Mario Advance 4: Super Mario Bros. 3: Classic World 1-1.
 * New Super Mario Bros.: A Mario vs. Luigi stage, though it is truncated (the first and fourth pipes are absent, as is the section between the blocks the Goombas walk on and the second staircase arrangement, with the stage looping after that).
 * Super Paper Mario: Lineland Road.
 * Super Smash Bros. Brawl, Super Smash Bros. for Nintendo 3DS, and Super Smash Bros. Ultimate: Mushroomy Kingdom.
 * New Super Mario Bros. Wii: World Coin-2.
 * New Super Mario Bros. 2: Part of the first stage of the Gold Classics Pack.
 * NES Remix 2: Recreated in Super Mario Bros. 3's engine similar to Classic World 1-1, as the first of the Bonus stages.
 * Super Mario Maker for Nintendo 3DS: As the first level of the Super Mario Challenge.
 * Super Mario Odyssey: In a theater in the Metro Kingdom.
 * Super Mario Maker 2: Super Mario Bros. W1-1?.
 * The Super Mario Bros. Movie: The construction site Mario and Luigi run through has the number plaque of the nearby building, the crates and cans on the scaffolding, and the vent above them positioned in the same layout as the first set of blocks in the level.

Trivia

 * A license plate in the Mario Kart: Double Dash!! course Mushroom City has "W 1-1" written on it, referencing World 1-1. The same license plate can be seen on cars in Moonview Highway in Mario Kart Wii.