to do this, get a cape. do valley of bowser 2 and at the part with the moles in the pits,
don't go in the first pit. get a running start with your cape and fly up in the pit.
when you are in the air, go left so that your hitting against the left wall. when you are
out of the screen, keep going left until you are on the platform. even though you are out
of the screen, keep going left and you will see a pit with a key and a keyhole. put the
key in the keyhole and your done.