Yazd city is located 270 km (170 mi) southeast of Isfahan. At the 2011 census, the population was 529,673 (269732 male and 259941 female), and it is currently the 15th largest city in Iran. Since 2017, the historical city of Yazd is recognized as a World Heritage Site by UNESCO. Because of generations of adaptations to its desert surroundings, Yazd has a unique Persian architecture. It is nicknamed the City of Windcatchers. Yazd is the driest major city in Iran, with an average annual rainfall of only 60 millimeters (2.4 in), and also the hottest north of the Persian Gulf coast, with summer temperatures very frequently above 40 °C (104 °F) in blazing sunshine with no humidity. Iran currently has 24 world heritage sites, more than any other country in the Middle East. Yazd is a city in central Iran and the capital of the Yazd province. It is an ancient city dating back to the Sassanid Period (224-651 AD). Yazd is located midway between Isfahan and Kerman, 689 km (427 miles) southeast of Tehran. Yazd is well connected to the rest of the country by planes, trains, and buses. Yazd, located between the Dasht-e Kavir and the Dasht-e Lut deserts, is one of the oldest cities in the world. It is known for the wind Catchers, or badgirs, built on its houses and for the beautiful weavings created by its craftspeople. Yazd populace is mainly Muslim. Yet, a large number of entire Iran's Zoroastrians inhabit here. Minorities of Jews and Christians also live here. Yazd is surrounded by mountain ranges of Shir-Kooh and Kharanegh. The city dates from Sassanid era (2000 years ago), and was called in those days "Isatis". The word Yazd means Clear of Filth . It also means Worship, Praise and Adoration. The appellation of the city is "The City of Gods". Yazd is the second Mud-Brick city in the world remaining from ancient times. The population is Aryan in the race and due to the isolated location of the city, the race has not intermingled with non-Aryans. The city covers 2491 square meter of the area and stands the warm and dry climate. Yazd is a Two-Season city with extreme climate (frosty winters and scorching dry summers). It is the first Iranian city registered in World Heritage. Yazd is among the unique historical provinces in Iran and one of the most beautiful mud-brick cities in the world. The wide range of tourist attractions brings all through the year tourists from around the globe. The city has acquired many titles throughout centuries: the City of World's Wind-Catchers, The City of Bicycles, The City of Sweets, The City of Qanats, and The city of Fire and Sun.