Secret Course 16
From the Super Mario Wiki
The course starts with a few Dry Bones and a green Koopa Troopa. The first Bonus Medal is found by jumping on one of the enemies. Next is a soft platform with another green Koopa Troopa. The player must kick either Koopa Troopa to have its shell obtain the second Bonus Medal, which is above a small gap. There are then more Dry Bones and another green Koopa Troopa among them. The player must once again kick the Koopa Troopa's shell and follow it, which will collide with some Big Spinies. The third Bonus Medal is above the first Big Spiny and the fourth Bonus Medal is obtained when the shell collides with it in a gap. After that are a few small gaps with Munchers, Dry Bones, and another green Koopa Troopa. There are also more Dry Bones and a red Koopa Troopa on Brick Blocks. The player must kick the red Koopa Troopa's shell into a gap with Munchers, which has the fifth and final Bonus Medal before the Goal Pole.