Tabriz is the fourth largest city and one of the historical capitals of Iran and the capital of East Azerbaijan Province. Situated at an altitude of 1,350 meters at the junction of the Quru River and Aji River, it was the second largest city in Iran until the late 1960s, one of its former capitals, and residence of the crown prince under the Qajar dynasty. The city has proven extremely influential in the country’s recent history. Tabriz is located in a valley to the north of the long ridge of the volcanic cone of Sahand, south of the Eynali mountain. The valley opens out into a plain that slopes gently down to the northern end of Lake Urmia, 60 kilometres to the west. With cold winters and temperate summers the city is considered a summer resort.The estimated population of the city is around 3,000,000 based on results of the Iranian census bureau. Tabriz is the fifth most populous city in Iran after Tehran, Mashhad, Isfahan, and Karaj. Tabriz is a major hub for heavy industries including automobile, machine tools, oil and petrochemical and cement production.With a rich history, Tabriz contains many historical monuments, but repeated devastating earthquakes and several invasions during frequent wars have substantially damaged many of them. Many monuments in the city date back to the Ilkhanid, Safavid, and Qajar periods, among them is the large Tabriz Historic Bazaar Complex which is inscribed as a World Heritage Site in 2010. The oldest signs of the civilization in the city is an excavation site and museum in the city center with a history that dates back 2500 years.