how do you get to that castle

Secret Exit:

To use this exit, you must have a cape. Use your cape to kill the Mega Mole
running around the pit, and run to the pit's right wall. Get a good starting
run, and fly up to the left into the large gap in the ceiling. If you flew
high enough, you should be out of view, and the screen should be moving left at
a fast rate. When you see the key and the keyhole on a bumpy pile of stone
blocks, immediately stop, and try to drop down on the right side. If you land
on the left, there is a possibility that you may fall in the small gap and die.
Now simply grab the key, put it in the keyhole, and you are done! Excellent
Job!! You found the secret exit to Valley of Bowser 2!!

what like place do u go in to do that

what pit?! What are you talking about?