Super Mario World/Star Road/Star World 1

Key

By spin jumping along the right edge of the level you will be able to reach the key easily.

Baby Red Yoshi

A Baby Red Yoshi is found in the bottom portion of the level, but it's hard to get, and will need a bit too much food. If a Red Yoshi is desired, it may be easier to instead find it on really think you should use Star World 4.