Isfahan or Esfahan (Persian: اصفهان Esfahān), historically also rendered in English as Ispahan or Hispahan, is located about 340 km south of Tehran and is the capital of Isfahan Province and Iran's second largest city (after Tehran). Isfahan city had a population of 1,583,609 and the Isfahan metropolitan area had a population of 3,430,353 in the 2006 Census, the third most populous metropolitan area in Iran after Tehran.
The cities of Najafabad, Khaneh Esfahan, Khomeini-shahr, Shahin-shahr, Zarrinshahr, Mobarakeh, Falavarjan and Fouladshahr all constitute the metropolitan city of Isfahan.
Isfahan is located on the main north-south and east-west routes crossing Iran, and was once one of the largest cities in the world. It flourished from 1050 to 1722, particularly in the 16th century under the Safavid dynasty, when it became the capital of Persia for the second time in its history. Even today, the city retains much of its past glory. It is famous for its Islamic architecture, with many beautiful boulevards, covered bridges, palaces, mosques, and minarets. This led to the Persian proverb "'Esfahān nesf-e jahān ast" (Isfahan is half of the world).
The Naghsh-e Jahan Square in Isfahan is one of the biggest city squares in the world and an outstanding example of Iranian and Islamic architecture. It has been designated by UNESCO as a World Heritage Site. The city also has a wide variety of historic monuments ranging from the Sassanid to the Safavid dynasties.[citation needed] Remaining Islamic architectural sites were built from 11th to the 19th century, while older, pre-Islamic monuments date back to 1000 B.C