Where is the cheese on Astro Knights Island?

There is some moldy cheese in the castle dungeon. To get to it :

1. Get the shiny gold coin in the fountain
2. Go to the Mordred Museum and use the coin
3. Find the library slip on the books to the right.
4. Go to the castle library (first floor to the right)
5. On the lower aisle, Non-Fiction, click on McM
6. Go down the secret passageway to the dungeon
7. Get the cheese (and pull the switch while you're there)

The Moldy Cheese is in the dungeon on the floor.