Tabriz is the capital of east azerbaijan province and is one of the largest cities in Iran . It is located in the Aji Chay Valley. The distance from Tehran is 624 kilometers and Tabriz-tehran railway line is 736 km. The city has located in the eastern corner of the sedimentary plain, with a moderate slope toward Lake Urmia. The city was the first capital of safavid dynasty and was known as the fifth largest city in the world at that time.