What would happen if the legend of the lost City of Atlantis was crossed with the screenplay for Kevin Costner's 1995 hit movie "Waterworld?"
Maybe something like The Ocean Spiral -- an underwater metropolis which generates its own energy from the seabed, produces food from deep sea aquaculture and is capable of providing accommodation for 5,000 people. Courtesy Shinzu Corp
Such blue-sky thinking may only seem plausible in the world of Hollywood CGI -- but this is the futuristic concept proposed by Japanese architecture firm Shimizu Corp.
According to literature released by the company, expertise is being sought from Tokyo University, Japanese government ministries as well as energy firms to bring the ambitious project to life. Courtesy Shinzu Corp.
Divided into three distinctive zones, the structure will stretch all the way to the crushing black depths 2.8 miles under the sea.
A giant sphere with a diameter 500 meters (1,640 feet) situated just below the surface will form the first section and house residential zones, businesses and hotels.
Residents and visitors will enter via the upper level of the facility here. Courtesy Shinzu Corp.
This inhabited area will be connected to a nine-mile spiral (section 2) that will descend to the seabed where a deep-sea submarine port and factory (section 3) will create the energy required to power the sphere by using micro-organisms found there to turn carbon dioxide into methane.
Power generators situated along the spiral will then use differences in seawater temperature to create additional energy by applying thermal conversion technologies. Courtesy Shinzu Corp.
Shimizu say projects like the Ocean Spiral may be necessary in the future to confront problems such as rising sea levels and the need to create new, clean energy sources.
According to a statement from the Japan Agency for Marine-Earth Science and Technology, a national research institute which is providing data to Shimizu for the project, it is vitally important "to promote maritime innovations in areas ranging from the use of marine resources to the deployment of marine biotechnology."
The agency adds that the research which will have to be carried out to make the Ocean Spiral viable will also "advance our understanding of the sea and earth." Couresy Shinzu Corp.
Shimizu has a history of imaginative high-concept projects including a space hotel and floating botanical cities, although none of these have actually come to fruition yet.
The company says the Ocean Spiral would take five years to build and the technology required to make it a reality will be ready in 15 years. Courtesy Shinzu Corp.
Funding for what is likely to be a cash intensive exercise will also have to be secured.
Until such times arrive, however, all we're left with is a series of cool artist renderings to whet (or should that be wet?) the appetite. Courtesy Shinzu Corp