This is a Bâdgir an ancient air conditioner invented around the eighth century AD.

Despite using no electricity, it has a cooling system that kept houses at a pleasant temperature during the hot summer months. However in the winter the buildings still remained warm and comfortable. These buildings are found across Iran but they are most prevalent in the ancient city of Yazd.

As you can see this city is surrounded by extremely dry arid desert conditions, the climate is pretty extreme with the hottest month being July which has an average temperature of around 38c or 102°F and the highest recorded temperature in the city was a whopping 46°C that's 115°F, There is also little to no rainfall throughout the year, with the average annual rainfall being somewhere between 0.4 – 0.7 mm.

Its crazy to think even today most building do not have modern air-conditioning but instead they still rely on the ancient air-conditioning systems this is because unlike powered air-conditioning and fans, Badgirs are silent and continue to function when the electrical grid power fails.