Karaj is located in 36 km west of Tehran, on the western shore of Karaj’s river and on the south hillside of the Alborz mountain range.
The vast plains of Karaj at the height of 1320 m above the sea level are on the way of vehicles transportation, roads between Turkey and Azerbaijan borders to Tehran and vice versa. Karaj consists of 2 districts named "Markazi" and "Eshtehard" and 7 rural districts after the separation of Shahriar, Robat Karim and Savojbolagh.
It is the fifth populous city in Iran after Tehran, Mashhad, Isfahan and Tabriz and is one of the Iran metropolises on the basis of the youth range rate. This city has a special situation in terms of having industries, universities, agriculture, tourism, ecotourism and cultural heritage centers.
Karaj is the biggest destination of immigration after Tehran in Iran and due to this huge immigration in number, multiethnics such as Fars, Kurd, Turk, Mazandarani, Lur, Gilak, Yazdi and Khozestani in various religious and dialects live there.