World 1 (A.K.A. Princess Peach's Kingdom/Peaceful Hills) is the First World on New Super Mario Bros. Wii, containing six Levels, a Tower, a Castle, a Warp Cannon and a Main Boss, named Larry Koopa. Three Special Stages - The Mushroom Houses (Red & Gold) - As well as housing Princess Peach's Castle. There are Three Special Stages, two Red Toad Houses, and one Golden Toad House; The two Red Toad Houses occurring upon completion of World's 1-2 and 1-4, and the Gold Mushroom House occurring upon the completion of World 1-3. The Element of that World is Grass.


Level Unlocks Preview Description
1-1 World 1-2 NSMBW1-1.PNG The First Level of New Super Mario Bros. Wii, showing the First Enemies ever: Goombas & Koopas. This Level is Designed for New Players.
1-2 World 1-3, Red Mushroom House 1-2NSMBW.PNG The First Underground Level of the Game. This Level show Piranha Plants.
1-3 World 1-Tower, Gold Mushroom House, 1-Cannon NSMBW1-3.PNG This Level is the First Ever to Reveal Yoshi, the Mount of the Game. Yoshi can Swallow Fruits and certain Enemies , Swallowing 6 Fruits will make Yoshi drop an Egg , giving You an 1-Up or a random Power-Up. This Level also contains A Secret Exit , Going Up to the Highest Plains and entering the Hidden Pipe.
1-Cannon World 5-1 N/A The Warp Cannon of World 1, leading directly to World 5. It is Unlocked by Finding the Secret Exit of the Level 1-3.
1-Tower World 1-4
World 1 Fortress.PNG
The First Tower , with Stone Platforms moving to try Smash You. Larry Koopa awaits You in the Top of the Tower.
1-4 Enemy Area, World 1-5, World 1-6, Red Mushroom House 1-4 nsmbwii.png This is the First Underwater Level , showing Cheep-Cheeps , Deep-Cheeps and Eep-Cheeps.
1-5 World 1-Castle 1-5 nsmbwii.png The First Athletic Level , with Koopa Para-Troopas. And it also Features Mushrooms that is Screw-Controlled.
1-6 World 1-Castle 1-6 nsmbwii.png A Common Plains Level filled with Koopas , Goombas , Piranha Plants and also Koopa Para-Troopas. Including Rolling Hills.
1-Castle World 2-1 , World 2-2 1-castle nsmbwii.png The First Castle Level , with many Giant Cogs and Thwomps. The Boss is still Larry Koopa.