|World location||Special 1|
|Previous level||Special 1-4|
|Next level||Special 2-1|
|Game(s)||Super Mario 3D Land|
In design and layout, the level is based on World 1-Castle, however, Mario has only 30 seconds on his clock to beat the level. To compensate this, the level is riddled with + Clocks to raise Mario's timer. After passing through the first half of the level, Mario is confronted by Dry Bowser, and a battle similar to those against Bowser throughout the game ensues.
Enemies that appeared in Special 1-Castle:
Dry Bowser's attack patterns are virtually the same of the Fake Bowser fights from the game. Cosmetically, Dry Bowser's breath attacks are a blue flame whereas the original Bowser attacks are a fiery orange. Dry Bowser is defeated in the same way Fake Bowser is – by using the switch at the end of the bridge to his castle. By the switch, Mario can also obtain a 100-second + Clock.
- Star Medal 1: The first Star Medal can be obtained by jumping on top of the long Question Block past the large gears early in the level.
- Star Medal 2: The second Star Medal is found above a + Clock after a confrontation with two Hammer Bros.
- Star Medal 3: The final Star Medal is above the second Thwomp of the level.