New Super Mario Bros. U: Sparkling Waters- Fort -- Giant Skewer Tower

The pipe in the first room leads to a water-filled room with lots of skewers, which are spiked pillars Some of the Star Coins are hidden in invisible area. The first Star Coin is in the left alcove of the first spike pillar. In the alcove of the second spike pillar is a Red Coin Ring. The second Star Coins are near the Red Coins. Go up past the Dry Bones to more spike pillars. There are platforms amongst spike pilllars. Go to the right ledge for some blocks to reach the high platform. Near the top of this section of the tower is a green pipe. On the left side of the wall is the face of Bowser Jr., near a giant Dry Bones. Behind the face is an invisible area with a red pipe. Both pipes lead to the midpoint, but the red pipe lets you access a P-Switch that makes Silver Coins. This area also has spike pillars. Over the next one you see is the third Star Coin, so be careful getting it. You'll want to stay away from the note blocks until you're ready to jump. Hit the note blocks from below for coins and items. On the second level in an invisible area is a POW Block. It can help you get the Star Coin. At the top is the boss door.  Kamek uses his magic to make Boom Boom jump higher in the arena, which has a little water in it. Stomp him as usual. The path to the Ghost House opens up. Farther away, Peach's Castle is surrounded by a vortex. Peach calls for help.