New Super Mario Bros. U: Rock-Candy Mines-7 -- Shifting-Floor Cave

This level has more of the orange platforms you can hit from below. Use them to reach the pipe to an underground area with Spike Tops and bats. Ahead are the shifting floors- walls and floors that appear from central pillars. You'll have to time your jumps because some pillars make walls to block you off and make you fall into the void. The first Star Coin is in a set of three pillars. Drop down when there's a floor below it. Be aware of the giant piranha plants on the ceiling. Past them is the midpoint. Past the midpoint are Spike Tops on some orange platforms. After that are more shifting floors. One part of the floor moves straight up. Jump up as Super Mario to break the brick blocks overhead, then run over the ceiling for the second Star Coin. Next is a Koopa and giant Piranhas on a moving floor with no gaps. Use the shell to kill the Piranha Plants, then use it to get the third Star Coin, which is under the pipe at the end. The pipe will take you to the flagpole. This opens the path to the castle, a Mushroom House, and loops back to the path after the first Fort, for easier navigation.