This is a plan of a vertical city in the middle of the ocean. Due to scarcity of dry land, the city is built vertically to optimize the use of available space. The city is built inside a crater of a dead volcano. People from the lower class live in the bottom of the crater. They enjoy less sunlight, no ocean view and no flat land, unlike the rich who live on top of the crater. Jesse van Dijk, a concept artist from Amsterdam, sees this as an optimal city design in the world where there is little dry land available.