Season 5 Episode 15 : Atlantis SquarePantis
When SpongeBob and Patrick find the second piece to the ancient Atlantian amulet, the gang all travel to the ancient city of Atlantis were their adventure starts. There they meet Lord Royal Highness, who takes them on the grand tour. As the episode goes on, Mr. Krabs buries his pockets with gold, while Plankton tries to take over, and SpongeBob and Patrick pop the treasure of Atlantis.