New Super Luigi U: Sparkling Waters- Fort -- Shish-Kebab Tower

This fort features spike pillars. Climb past the Fire Bros and take the elevator behind the grate. While the elevator is rising, go to the right. Behind the green Bowser Jr. face on the wall is a hidden area with the first Star Coin. Take the elevator to the top and keep climbing. The second Star Coin is in the corner on the right with the spikes. Take another elevator up and you'll see a Luigi image on the side. The third Star Coin is above the image. Go left of the Fire Bro and pound the brick blocks to get it. At the top is the boss door. Kamek's magic will let Boom Boom jump and spin. Hit him three times to win. Outside, the clouds surrounding Peach's Castle get thicker.