Atlantis

Lord Royal Highness inviting SpongeBob and Patrick in Atlantis.

Atlantis is the place that SpongeBob SquarePants and his friends visit in Atlantis SquarePantis. As seen in the episode, the place is very high tech with things never seen before. The king of the city is Lord Royal Highness. It is also home to the world's Oldest Living Bubble, which Patrick Star accidentally popped. Atlantis has also been seen in Neptune's Spatula. Atlantis made its first main appearance in the aforementioned "Atlantis SquarePantis." Atlantis was usually the home for King Neptune, although Neptune wasn't Atlantis' king (but Lord Royal Highness was).

In Mermaid Man and Barnacle Boy, SpongeBob talked about Atlantis where the city's food supply was running low, so Mermaid Man invented a 6-time ray gun that can increase anything's size multiplied 6 times but Man Ray stole the ray gun and shot it at all the algae.

City Areas

• The Castle: Where L.R.H. lives and where the door to the weapon room is locked with a combination lock. Mr. Krabs finds out at this part that both cases of Squidward saying "The streets are made of gold and the lamps are made of diamonds" are not true.
• Treasure Room: Eugene H. Krabs' favorite room and the room where he sings "All This Money." All of the treasure of Atlantis belongs here. The people of Atlantis don't want it, so they give it to anyone they please.
• Science Room: Sandy Cheeks' favorite room and the room where she sings "The Germ Warrior." All inventions made by the city are held in this room. It has a machine that transports you inside the machine and renders you so small that you can battle germs like a video game.
• Armory Room: Sheldon J. Plankton's favorite room and the room where he sings "So Many Weapons." All weapons that they no longer use is locked shut and is unguarded. The weapons shoot only ice cream, much to Plankton's dismay ("Ice cream? IT SHOOTS ICE CREAM?!").
• Art Room: Squidward Tentacles' favorite room and the room where he sings "Pick up a Pencil." Lots of great art projects are held in this room and visitors can go through all sorts of paintings they can think of.
• Tourist Area: The fake version of the oldest bubble for tourists to see is held here. L.R.H. held the real one when Patrick took a picture and popped it.
• Dining Room: Dinners and meetings are held here.
• Atlantis Garden: Outside the building that L.R.H. was in, there's a garden that SpongeBob and friends accidentally destroy. Squidward complained that it shouldn't have been destroyed.
• Bacteries area: It is featured as the second variant of 6th level in SpongeBob's Atlantis SquarePantis.
• Neptune's Palace: King Neptune's home where Gods live and where chosen fry cooks are chosen to cook for. It is a parody of a temple near Athens, and Thessalonica, Greece.
• The Poseidome: Where the Ultimate Cook Off is held. It also serves as a place to bid on who will win the competition. Its name is also a parody of the Greek God Poseidon.