World 2-3 (Super Mario Bros.)

World 2-3 is the third level of World 2 in Super Mario Bros. and the seventh level overall in said game.

Layout
World 2-3 is made up of long bridges the player must run and jump across while avoiding an endless array of jumping Cheep-cheeps. If the player is running, the Cheep-cheeps will usually jump up behind the player, though if the player is walking, they will jump from the front and there is a high chance of the player getting hit. The player also needs to jump across some small platforms that are placed in the second half of the stage. In the only ? Block is a power-up. If the player reaches the stone steps at the end, the Cheep-cheeps will stop jumping from below.

In Hard Mode, this level is a clone of World 7-3, and features Koopas.

Super Mario Bros. Deluxe challenges
In Super Mario Bros. Deluxe, the player 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 directly in the center of the second grass platform, and the score to beat is 23000. The Red Coin locations are:
 * Over the second bridge with the other coins
 * Just before the grass platform in the middle of the level, over the gap
 * On the edge of the low platform
 * Above the center small platform
 * On the ground next to the flagpole

Level map
Mondo 2-3 (Super Mario Bros.)