Tehran is the capital of Iran and and the administrative center of Tehran Province. Tehran is one of the largest and most populous cities in the world, with a population of 13 million. Tehran has been the nation’s capital for two centuries and now it is one of the biggest cities in the world and the most populated city in Iran. The City, which grew out of the ages, is becoming one of the most beautiful cities in the Middle East while maintaining its cultural and historical identity. Historical palaces such as Shams-ol-Emareh, Golestan, and Sa’ad Abad, which once were the tallest and strongest buildings in Tehran, prove how creative Iranian artists and architects have been. Mosques such as Sepah Salar, Imam, and Sheikh Abdol Hossein, the Traditional Bazar of Tehran, and museums like Iran Bastan, Reza Abbasi, Golestan, Abgineh, and Sofalineh are all signs of the several thousand year old Iranian heritage. Tehran, now a great metropolis, lies on the southern slopes of Central Alborz, and has extended in all directions in recent years.