WP #170, Egg #14 & #15
The Depths (みなぞこ, Minazoko) is an area accessible from the blue passage in the Square Ruins.
A peaceful underwater area, similar to Atlantis, but much darker as it is apparently located deep in the ocean. Various types of jellyfish roam the area, and this map features and unusually large number of teleport nodes. Somewhere in the map, there is a manhole with a ladder inside, which leads to the Aquarium.
There is a brown teleport node that takes you to an event where you see Urotsuki floating downwards until the screen blacks out. After landing, Urotsuki lays down in a new blocked-off area in front of to what appears to be wreckage. The music is peaceful ambience with piano notes. It is impossible to return from this area.
A dark area with a large window, essentially an outlook to the ocean floor. The ambient light here changes randomly, in a subtle way. Apart from adoring the view, there is nothing much to do here.
Nexus → Red Streetlight World → Gray Road → Grass World → Green Neon World → Construction Frame Building → Cog Maze → Forest Pier → Abandoned Factory → Arc de Pillar World → Flooded Ramparts → Mansion → Deserted Pier → Deserted Town → Chaotic Buildings → Antenna World → Complex → Old Train Station → Cosmic World → Square Ruins → Depths
As of version 0.100e this location is the furthest removed from the Nexus, making it the deepest part of the dream world, with 19 individual locations (Assuming you entered Abandoned Factory from the Forest Pier) between the Nexus and the Depths.