Tehran became the capital of Iran under the Ghajar rulers in 1789 and has changed from a sleepy town to a mega-metropolis with around 12 million residents. It is towered by Alborz mountains and Lavizan, sheeyan woods on the east side. Although tehran is a fairly new city, came to existance 17th century but the southern part now known as Rey has such a long history. Tehran is also part Media, a part of late Iran. In times of the previous rejime lots of people moved to Tehran for the industrialization and modernization going on, today the traffic, pollution has changed the minds.