The Ocean is an unnamed area, taking up an apparent majority of the earth that the story takes place in. The Ocean is vast and it's unknown how far out it goes. The Ocean is where the Admirabilis originated from, and where some have returned to.
The Ocean is much more barren than the Earth currently has, having long sections with no objects or features. It seems to be that way since the Admirabilis all resided there as they suffered from food shortages.
Landmarks and Architecture
Currently there are no known landmarks or architecture. Ventricosus does remark that a certain spot is "home" although it doesn't look much different than the previous sections. It's unknown if the Admirabilis currently or previously had buildings and architecture, as there seems to be a hierarchy.
The central species that resides in the Ocean are the Admirabilis. They are the one of the three descendants from humanity, known as the Flesh. They are the organic descendant and are the only one to have a life and death cycle.