There has been much talk of a “Minus World” in SMB, and Jed Smith of Colrain, Massachusetts, tells as how to get there. In World 1-2, stand on the pipe shown and break the second and third bricks from the right. You must be a large Mario to do this. Position Mario at the left side of the pipe, with one foot hanging off the edge. Using A, jump up and move the controller to the right, being careful not to break the single brick.
If you time it correctly – you’ll likely have to try this a few times to succeed – you will be pulled through the wall to a bonus area. Select the first or third pipe to go to the watery Minus World. Great work, Jed.