Atlantis is an area accessible from the Snowy Pipe Organ in Marijuana Goddess World.
Features
The world is essentially under the sea and is reached by interacting with the piano. There are a number of blue coral branches and bubbles rising up from the sand. Shoals of fish will pass by periodically. If you go straight up from the piano, you'll find a throne room with a big pink chair at the top of it.
If you use the Penguin effect in this world, you will be able to swim constantly without having the need to keep pressing the arrow keys.
The Reef
This area is reached by going down from the piano. There are a number of large fish swimming around this area. There is also a large group of small rocks around this area, with a ghost of Urotsuki sitting in the middle of them. If you keep swimming down, you will find some houses made out of blocks of sand with bridges across them. You will also see a big brown blob with a face (that looks like feces) that starts blushing and having a nosebleed if you use the Penguin effect around him. Wandering on the buildings can take you to a doorway which leads to the Realistic Beach.
The City
By using the Fairy or Child effect at the hole in the wall behind the pink throne, you'll get to the city. There is a road and a number of tall buildings here. You can also see Tako Otoko standing in the open. By going through one of the doorways, you'll come to the entrance to Tapir-San's Place.
If you continue right, you'll reach a long road populated by blue figures (some of which are just floating in the foreground). Weave in and out of them to keep going right and you should reach the Underwater Amusement Park.
Connections
Realistic Beach (one way, unless specific requirements are met)