From the Super Mario Wiki
The Mecha Castle is a level in the Nintendo 64 game Yoshi's Story, and is widely considered to be the easiest of the castle levels on the final chapter. It is home to many large sharp blue and red weapons that are referred to as Swords. Gears are also abundant here, as well as spinning wheels much like the ones from Yoshi's Island. Some Compressors smash together, instantly defeating any Yoshi traversing the castle.
 Other Information
 Storybook Segment
The Yoshis finally got to the castle in the final page of the storybook. Behind all the noisy machines, Baby Bowser guarded the tree. Bowser was a tough baby, but bad guys finish last. The Yoshis won!
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