Kerman is the capital city of Kerman Province, Iran. At the 2011 census, its population was 621,374, in 171,389 households, making it the 12th most populous city of Iran. It is the largest and most developed city in the Kerman Province and the most important city in South-East Iran. It is 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 is also on the list of the recent world's 1000 cleanest cities. Kerman is also a former capital of Iran, a position that it held suring during several periods. It is located on a large, flat plain, 1,036km (643mi) south of Tehran, the capital of Iran.