AT Design Office, with venues in England and China, has been commissioned by the Chinese building firm CCC, to design an island with an area of 10 square kilometers, using the latest technology. The “underwater cities” may offer an alternative housing in the future, especially because of the problem of overpopulation of the planet. Thus was created a metropolis under water. The proposed design is based on a series of prefabricated hexagonal modules, which would be built across the city, from buildings to boats. Public green areas and farms would be found on the water level. Small gardens would be located underwater. An important part of this project would be a 150 meters long subaqueous tunnel, that would connect the city with the surface.