Go near the entrance of Dire, Dire Docks (the level that is in the wall behind the second Bowser area). Note that the behind the blue gook seems to be a path that continues onwards. Now, go to either wall and slowly slide along the wall, to the entrance (so that Mario's pressing his chest against the wall and scooting along it). Keep on going. If you do it carefully enough, you will pass through the entrance of the level, without going into the level. Unfortunately, there is an invisible wall behind the level, preventing you from going on that path behind it. If you make Mario crawl, the invisible wall will make his head disappear, because it will be going through the wall. If you try moving along the invisible wall, or part from the wall you were scooting against, then you will enter the level.
Submitted by: Connie