No, this isn't Discworld — there aren't any elephants — but it's as close as humans will get to Terry Pratchett's comic fantasy world. The Pangeos Terayacht concept is a floating city housing 60,000 people in a floating, turtle-shaped vessel measuring 1,800 feet. The name Pangeos is a reference to the prehistoric supercontinent of Pangea, and in terms of seaborne transportation, it's continental in size. The Pangeos floats on 30,000 individual cells, propelled and powered without emissions by solar panels driving nine 16,800 horsepower engines at a top speed of five knots. The "flippers" could also theoretically generate power from waves and wind. Residents would stay in a combination of villas and apartments, with a mall, gardens, pools, and beach club for recreation. Facilities for tenders, helicopters, and hangers allow for transportation to and from the vessel. A shipyard big enough to build the behemoth would be needed, with designer Lazzarini estimating eight years and $8 billion for completion.