
Sustainable city developer URB has unveiled its plans for the world's largest ocean restoration project, Dubai Reefs, shown here in a rendering.

The proposed design would consist of 77 square miles of artificial reef that could create a home for more than one billion corals and 100 million mangrove trees.

If built, the site would also be home to a marine institute dedicated to ocean research and protecting Dubai's coastal environment.

The design also includes floating hospitality and retail facilities, and various eco-lodges, which would make the site a destination for eco-tourism.

URB says that the whole site would be powered by 100% renewable energy, generated from solar, hydropower and wave farms.

The Dubai-based developer specializes in sustainable city designs. Earlier this year, it released a design for a 93-kilometer (58-mile) indoor cycling super highway, shown here in a rendering, that would wrap around the city.

If built, the project, known as "The Loop," would provide a car-free, climate-controlled "green corridor" for residents to walk, cycle, or run around the city.

Another environmentally conscious design proposed by URB is the "Agri Hub." Pictured in this rendering, the project would be a center for sustainable agriculture and tourism in the desert outside of the city of Dubai.

URB has also designed projects outside of Dubai, such as a 580-hectare sustainable city for Cairo, shown in this rendering, which aims to produce more energy and food than it consumes.