Forest Secret Area
From the Super Mario Wiki
The level is a large gorge that can be crossed over by two flying platforms of three Rotating Blocks; jumping on either platform will trigger the level to scroll, and both platforms will ascend and descend alternately. Koopa Paratroopas roam the sky and congregate in flocks, guarding various intermittent power-ups and Dragon Coins. About halfway through the ride, the player comes to a small island comprised of blue Exclamation Point Blocks where an extra life can be earned inside a Rotating Block. Shortly after, just beyond the Giant Gate rests three 1-Up Mushrooms that can only be reached by flying over the Post with a Cape Feather or Blue Yoshi.