The idea of a floating island for the rich seems to bubble up every year or so.
There was the project called the "WHY 58X38," a 10,000-square-foot motorized island announced in 2010 that could rove around the world with its own beach and pool. Then there was "Utopia," the 200-foot-tall "floating city" that had its own restaurants, shops and homes.
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Then there's the Seasteading Institute, a group founded with billionaire venture capitalist Peter Thiel that hoped to launch a "visa-free" ship for tech workers by 2014.
So far, none has become a reality. But that hasn't stopped the biggest-ever idea for a floating city from ascending back into the limelight.