Roy's Conveyor Castle

Roy's Conveyor Castle, or  is the castle of Rock-Candy Mines in New Super Mario Bros. U. This castle contains iron blocks that float on lava and Dry Bones. It is unlocked when Shifting-Floor Cave is completed and its own completion opens the path to Meringue Clouds and Land of the Flying Blocks. Additionally, the course can be entered via a Exclamation Mark Switch bridge to the backdoor of the castle. The boss of this stage is Roy Koopa.

Level Overview
The player will first ride an iron block across some hot lava and encounter a Dry Bones and a Bony Beetle. After that, he or she will pass by another Bony Beetle and ride on some more iron blocks in order to avoid the lava. On the way, the player may collect some coins. After that, the player will reach an area where he or she must hit a switch, thus causing a bunch of blocks to fall on top of the surface of the lava. The player can then get on top of them and make his or her way to the door. The player will then enter the door, launch his or herself out of the cannon, and proceed to fight Roy Koopa.

Star Coins

 * Star Coin 1: In order to get the first Star Coin, the player must allow the first iron block to fall on the surface og the lava and quickly dash towards the Star Coin.
 * Star Coin 2: While floating on an iron block in the middle of the level, the player must wall jump to a hidden Warp Pipe which leads to a hidden room. After entering the hidden room, the player must act quickly by dashing to the second Star Coin and back before an iron block falls.
 * Star Coin 3: Access to the third Star Coin requires the secret entrance in to the back of this castle on the world map. Next, the player must hit a switch in order to cause a bunch of iron blocks to fall overhead. After that, the player can now walk on top of the iron blocks and get the third Star Coin.

Enemies

 * Dry Bones
 * Bony Beetle
 * Bullet Bill (during the boss battle)
 * Missile Bill (during the boss battle)