Yazd is a centre of Zoroastrian culture. The city is located some 175 miles southeast of Isfahan. Yazd has a population of over a half million (533,000 according to and 522,000 according to). Because of generations of adaptations to its desert surroundings, Yazd is an architecturally unique city. It is also known in Iran for the high quality of its handicrafts, especially silk weaving, and its sweet shops. Yazd with the area of 131,551 km² is situated at an oasis where the Dasht-e Kavir desert and the Dasht-e Lut desert meet, the city is sometimes called "the bride of the Kavir" because of its location, in a valley between Shir Kuh, the tallest mountain in the region at 4075 m. above sea level, and Kharaneq. The city itself is located at 1203 m. above sea-level, and covers 16,000 km².
The city has a history of over 3,000 years, dating back to the time of the Median empire, when it was known as Ysatis (or Issatis). The present city name has however been derived from Yazdegerd I, a Sassanid ruler. The city was definitely a Zoroastrian centre during Sassanid times. After the Arab Islamic conquest of Persia, many Zoroastrians fled to Yazd from neighbouring provinces. The city remained Zoroastrian even after the conquest by paying a levy, and only gradually did Islam come to be the dominant religion in the city.
Because of its remote desert location and the difficulty of approach, Yazd had remained largely immune to large battles and the destruction and ravages of war. For instance, it was a haven for those fleeing from destruction in other parts of Persia during the invasion of Genghis Khan. It was visited by Marco Polo in 1272 who remarked on the city's fine silk-weaving industry. It briefly served as the capital of the Muzaffarid Dynasty in the fourteenth century, and was sieged unsuccessfully in 1350–1351 by the Injuids under Shaikh Abu Ishaq. The Friday (or Congregation) Mosque, arguably the city's greatest architectural landmark, as well as other important buildings, date to this period. During the Qajar dynasty (18th Century AD) it was ruled by the Bakhtiari Khans.
Under the rule of the Safavis (16th century), some people emigrated from Yazd and settled in an area which is today on the Iran-Afghanistan border. The settlement was named Yazdi. This place is currently on the Iran-Afghanistan border in the province of Farah, in Farah city in Afghanistan. Even today, these people speak with an accent very similar to that of the people of Yazd.
Yazd is of foremost importance as a centre of Persian architecture. Because of its climate, it has one of the largest networks of qanats in the world, and Yazdi qanat makers are considered the most skilled in Iran. To deal with the extremely hot summers, many old buildings in Yazd have magnificent windcatchers, and large underground areas. The city is also home to prime examples of yakhchals, the latter of which were used to store ice retrieved from glaciers in the nearby mountains. Yazd is also one of the largest cities built almost entirely out of adobe.
Yazd's heritage as a centre of Zoroastrianism is also important. There is a Tower of Silence on the outskirts, and the city itself has a Fire Temple, which holds a fire that has been kept alight continuously since 470 AD. Presently, Zoroastrians make up a significant minority of the population, around 20,000 - 40,000 or 5 to 10 per cent.
Built in 12th century and still being in use, Jameh mosque of Yazd is an example of finest Persian mosaics and excellent architecture. Its minarets are the highest in the country.