Title: List of largest cities of Iran
Content:   Iran has one of the highest urban population growth rates in the world. From 1950 to 2002, the urban proportion of the population increased from 27% to 60%. The United Nations predicts that by 2030 80% of the population will live in urban areas. Most internal migrants have settled near the cities of Tehran, Isfahan, Ahvaz, and Qom. Tehran, with a population of 8.7 million (2016 census), is the largest city in Iran and is the nation's capital. Tehran is home to around 11% of Iran's population. It is the hub of the country's communication and transport networks. Mashhad, with a population of 3 million, is the second-largest Iranian city and the centre of the province of Razavi Khorasan. Mashhad 
Title: Iran
Content:  populous city of Iran, and had been the second most populous until the late 1960s. It was the first capital of the Safavid Empire, and is now the capital of the province of East Azerbaijan. It is also considered the country's second major industrial city (after Tehran). Shiraz, with a population of around 1.8 million (2016 census), is Iran's sixth most populous city. It is the capital of the province of Fars, and was also the capital of Iran under the reign of the Zand dynasty. It is located near the ruins of Persepolis and Pasargadae, two of the four capitals of the Achaemenid Empire.
Title: List of largest cities of Iran
Content:  one of the holiest Shi'a cities in the world as it is the site of the Imam Reza shrine. It is the centre of tourism in Iran and between 15 and 20 million pilgrims go to Imam Reza's shrine every year. The third most populous city of Iran is Isfahan with a population 1.9 million (as of 2016). This city is one of the most industrial cities of Iran with large industries and hosts several UNESCO World Heritage Sites. The city has a wide variety of historic monuments and is known for its paintings, history and architecture. The fourth most populous Iranian city is Karaj, with a population of 1.6 million (as of 2016). Karaj is the capital of 
Title: Iran
Content:  variety of historical sites, including the famous Shah Square, Siosepol, and the churches at the Armenian district of New Julfa. It is also home to the world's seventh largest shopping mall, Isfahan City Center. The fourth most populous city of Iran, Karaj, has a population of around 1.9 million (2016 census). It is the capital of the province of Alborz, and is situated 20 km west of Tehran, at the foot of the Alborz mountain range. It is a major industrial city in Iran, with large factories producing sugar, textiles, wire, and alcohol. With a population of around 1.7 million (2016 census), Tabriz is the fifth 
Title: Iran
Content:  cultural center, and is the hub of the country's communication and transport network. The country's second most populous city, Mashhad, has a population of around 3.3 million (2016 census), and is capital of the province of Razavi Khorasan. Being the site of the Imam Reza Shrine, it is a holy city in Shia Islam. About 15 to 20 million pilgrims visit the shrine every year. Isfahan has a population of around 2.2 million (2016 census), and is Iran's third most populous city. It is the capital of the province of Isfahan, and was also the third capital of the Safavid Empire. It is home to a 
Title: Tehran
Content:  Tehran ( Tehrān ) is the capital of Iran and Tehran Province. With a population of around 8.7 million in the city and 15 million in the larger metropolitan area of Greater Tehran, Tehran is the most populous city in Iran and Western Asia, and has the second-largest metropolitan area in the Middle East, after Cairo). It is ranked 24th in the world by metropolitan area population. It is also known for its sprawling development and futuristic architecture, epitomized by the Milad Tower and the Fereshteh Pasargad Hotel, designed by Zaha Hadid. In the Classical era, part of the territory of present-day Tehran was occupied by Rhages, a prominent Median city destroyed in the medieval Arab, 
Title: Kerman
Content:  Kerman (also romanized as Kermān, Kermun, and Karmana), known in ancient times as the satrapy of Carmania, is the capital city of Kerman Province, Iran. At the 2011 census, its population was 821,394, in 221,389 households, making it the 10th most populous city of Iran. It is the largest and most developed city in Kerman Province and one of the most important cities in the southeast of Iran. It is also one of the largest cities of Iran in terms of area. Kerman is famous for its long history and strong cultural heritage. The city is home to many historic mosques and Zoroastrian fire temples. Kerman became the capital city of Iranian dynasties several times during its history. It is located on a large, flat plain, 800 km (500 mi) south-east of Tehran, the capital of Iran.
Title: Isfahan
Content:  Isfahan, from its ancient designation Aspadana and later Spahan in middle Persian, rendered in English as Ispahan, is a major city in Greater Isfahan Region, Isfahan Province, Iran. It is located 406 km south of Tehran and it is the capital of Isfahan Province. Isfahan has a population of approximately 1.9 million, making it the third-largest city in Iran, after Mashhad and Tehran, and the second-largest metropolitan area. It is located at the intersection of the two principal north–south and east–west routes that traverse Iran. Isfahan flourished between the 9th and 18th centuries under the Safavid dynasty, when it became the capital of Persia for the second time in its history under Shah Abbas the Great. The city retains much of its history. It is famous for its Perso–Islamic architecture, grand boulevards, covered bridges, palaces, tiled mosques, and minarets. Isfahan also has many historical buildings, monuments, paintings, and artifacts. The fame of Isfahan led to the Persian proverb "Esfahān nesf-e-jahān ast": Isfahan is half (of) the world. The Naqsh-e Jahan Square in Isfahan is one of the largest city squares in the world. UNESCO has designated it a World Heritage Site.
Title: Iran
Content:  Iran is divided into five regions with thirty-one provinces (ostān), each governed by an appointed governor (ostāndār). The provinces are divided into counties (šahrestān), and subdivided into districts (baxš) and sub-districts (dehestān). The country has one of the highest urban growth rates in the world. From 1950 to 2002, the urban proportion of the population increased from 27% to 60%. Most internal migrants have settled around the cities of Tehran, Isfahan, Ahvaz, and Qom. The listed populations are from the 2006/07 (1385 AP) census. Tehran, with a population of around 8.8 million (2016 census), is the capital and largest city of Iran. It is an economical 
Title: List of largest cities of Iran
Content:  Province and is situated 20 km west of Tehran, at the foot of Alborz mountains; however, the city is increasingly becoming an extension of metropolitan Tehran. The fifth most populous Iranian city is Shiraz (population 1.57 million), which is located in the southwest of Iran with a moderate climate and has been a regional trade center for over a thousand years. Shiraz is one of the oldest cities of ancient Persia, known as the city of poets, literature, flowers. It is also considered by many Iranians to be the city of gardens, and also a major center for Iran's electronic industries. The other major cities are Tabriz (population 1.56 million), Qom (population 1.2 million), and Ahvaz (population 1.18 million).

Question: What is the capital of Iran?
Answer: Tehran.
Teheran.