Tall, chimney-like towers rise from centuries-old adobe houses in Iran's desert city of Yazd, drawing in a pleasant breeze for residents of one of the hottest cities on earth.
The wind catchers, called badgirs in Persian, are just one of the engineering marvels inhabitants have developed in this ancient city in central Iran — where temperatures reach well over 40 degrees Celsius in the summer.
And unlike energy-guzzling air-conditioners, they're cost and carbon-free.