Nain (Persian: نائین, also Romanized as Nā’īn and Nāeyn) is a city in and the capital of Nain County, Isfahan Province, Iran. At the 2006 census, its population was 24,424, in 6,950 families.
Na’in (also known as Naein and Naeen) lies 170 km north of Yazd and 140 km east of Esfahan with an area of almost 35,000 km², Na’in lies at an altitude of 1545 m above sea level. Like much of the Iranian plateau, it has a desert climate, with a maximum temperature of 41°C in summer, and a minimum of -9°C in winter.
More than 3,000 years ago the Persians learned how to construct aqueducts underground (qanat in Persianکاریز, or kariz) to bring water from the mountains to the plains. In the 1960s this ancient system provided more than 70 percent of the water used in Iran and Na’in is one of the best places in all the world to see these qanats functioning.
Unique to Na’in are some of the most outstanding monuments in all of Iran: the Jame Mosque, one of the first four mosques built in Iran after the Arab invasion; the Pre-Islamic Narej Fortress; a Pirnia traditional house; the Old Bazaar; Rigareh, a qanat-based watermill; and a Zurkhaneh (a place for traditional sport).
Besides its magnificent monuments, Na’in is also famous for high-quality carpets and wool textiles.
Some linguists believe the word Na’in may have been derived from the name of one of the descendants of the prophet Noah, who was called "Naen". Many local people speak an ancient Pahlavi Sasani dialect, the same dialect that is spoken by the Zoroastrians in Yazd today. Other linguists state that the word Na’in is derived from the word "Nei" (“straw” in English) which is a marshy plant.
It has one of the earliest remaining mosques in Iran, and has a Sassanid era fort, now in ruins, called Narin Ghal'eh.
It extensively uses ab anbars. Naein is most famous in the world for its rugs.