World 4-Castle (New Super Mario Bros. Wii)
From the Super Mario Wiki
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, horizontal long-reaching Skewers make their appearance throughout the first half of the level, as well as the last half of it. Wet 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 Magikoopa's magic, at times the water level rises, which renders jump attacks useless while Wendy is underwater. After getting hit three times, Wendy is defeated, and allow Mario and co. to get the key out of the castle.