World 4-Castle (New Super Mario Bros. Wii)

 is the Castle level of World 4 in New Super Mario Bros. Wii.

Layout
This course features fences that can be held onto, along with some Climbing Koopas that cling onto the fences. The player can sometimes also change which side of the fences they can hang on from.

Additionally, the spiked pillars that appeared in #6 Wendy's Castle and the Valley Fortress back in Super Mario World make an appearance here. However, they are all horizontal instead of vertical.

Fish Bones make their first appearance in this game here.

The player faces Wendy O. Koopa for a second time here and uses the same tactics as before. However, due to Kamek's magic, at times the water level will rise, which will render jump attacks useless while Wendy is underwater. After getting hit three more times, Wendy will be defeated, and allow Mario and co. to get the key out of the castle.

Star Coins

 * Star Coin 1: The first Star Coin is floating above the fourth Skewer, behind a grate platform. Mario and co. must find a grate platform with a door, hit the door, then return to the grate platform with the Star Coin and jump to it.
 * Star Coin 2: The second Star Coin is not far after the first one, between two Skewers. Mario and co. must wait for the Skewers to retract then quickly grab the Star Coin before they launch again.
 * Star Coin 3: Just under Wendy's door is a Green Pipe. Mario and co. should wait for the Skewer to retract, then go in the Pipe. Once there, Mario and co. should swim down to the third Star Coin while avoiding the Fish Bones.

Enemies

 * Skewers
 * Climbing Koopas
 * Dry Bones
 * Fish Bones
 * Spinners
 * Boss: Wendy O. Koopa