Secret Course 15
From the Super Mario Wiki
The course starts off with a Bob-omb and the first Bonus Medal next to a crate. The second Bonus Medal is found behind two crates stacked on top of each other that can be destroyed by the Bob-omb. Next is a soft platform with another Bob-omb and a crate hiding the third Bonus Medal. After that is another crate with a ? Block containing a Super Star. The Super Star can be used to grab the fourth Bonus Medal and many coins above a springboard. Lastly is a staircase of crates right before the Goal Pole. The fifth and final Bonus Medal is found among the crates and can be obtained by using the Super Star to attract it.