Ingenious windcatchers (badgirs) on the roofs of Yazd, which lies in the midst of the desert of the central Iranian plateau, were developed by the Persians several millennia ago as natural air conditioners. “The heat is tremendous, and on that account their houses are built with ventilators to catch the wind. These […] are placed on the side from which the wind comes, and they bring the wind down into the house to cool it. But for this the heat would be utterly unbearable.” The Travels of Marco Polo, Vol 2 Bk 2, Ch 40 Yazd, Iran