Dan Baum reports in the June 2013 issue of "Popular Science" that Masdar City has created a new take on an old idea. They have built a wind tower, 20 feet across and five stories high. It keeps the people on the desert floor of this city cool in the central courtyard. In fact, he says it was "keeping us cool with a stiff breeze." He describes it as a "hollow tower on steel legs. The tower acts as a wind catcher, drawing cool breezes from above the city and directing them down to the courtyard. The street-level breezes it generates are constant and virtually free. It's not a modern invention .... but Engineers at Masdar improved upon the tradition by mounting computer-operated louvers at the top of the structure to maximize its efficiency; the panels open and close according to prevailing winds. They also added misting units to cool the air even further."