|Version .020 (Main Area)|
|Version .020 (Jellyfish Room)|
|Version .030 (Main Area)|
|Version .030 (Jellyfish Room)|
The Atlantis World (うみ, Sea) is a peaceful deep sea area laden with chasms, coral, rocks, pillars, and plain white buildings, accessible from the Nexus via the top-right door.
There are 5 types of rocks in main area that appear when number of time Chie slept reach 4, 7, 10, 15 and 20 respectively. Eventually, the door connecting to the Nexus is surrounded by rocks creating the form of a circle.
There is a rare event that causes the rocks in the map to flicker. This has a 1 in 3001 chance to trigger in every 0.5 second interval while Chie stays in the main area. The BGM fades out and the rocks flicker with a twinkle sound. By the probability, the event may trigger once in every 25 minutes.
The area is inhabited largely by pale blue, featureless fish that swim past in the foreground, with a single dorsal and pelvic fin. Additionally, jellyfish of the same color can be found drifting about in one of the buildings.
However, it should be noted that many of the buildings scattered about seem vacant, implying a civilization may have once lived here but long since left, or that Chie feels an isolation towards other people, and this manifests itself in her dream world.