Tehran is the capital of Iran and Tehran Province.. It is ranked 29th in the world by the population of its metropolitan. Tehran was first chosen as the capital of Iran by Agha Mohammad Khan of the Qajar dynasty in 1796. Tehran is the 32nd national capital of Iran. The most famous landmarks of the city include the Azadi Tower, a memorial built during the Pahlavi period, and the Milad Tower, the world's 17th tallest freestanding structure which was built in 2007. The newly built Tabiat Bridge is considered as the 3rd symbol of the city. Tehran is served by the Mehrabad and Khomeini international airports, a central railway station, the rapid transit rail system of Tehran, as well as trolleybus and BRT systems, and has a huge network of highways. The City of Tehran is divided into 22 municipal districts, each with its own administrative center. 20 of the 22 municipal districts are located in Tehran County's Central District, while the districts 1 and 20 are respectively located in Shemiranat and Ray counties. Tehran has a wide range of shopping opportunities, from traditional bazaars to shopping districts and modern shopping malls. The Grand Bazaar of Tehran and the Bazaar of Tajrish are the biggest traditional bazaars in Tehran.