Iran, also known as Persia officially the Islamic Republic of Iran, is a country in southwest Asia. Iran is the country of mountains and deserts. Eastern Iran is dominated by a high plateau, with large salt flats and vast sand deserts. The plateau is surrounded by even higher mountains, including the Zagros to the west and the Elburz to the north. Its neighbors are Turkmenistan, Azerbaijan and Armenia on the north, Afghanistan and Pakistan on the east, and Turkey and Iraq on the west. Tehran is the capital, the country's largest city and the political, cultural, commercial and industrial center of the nation. Iran has played an important role in the Middle East, as an imperial power and as a factor in rivalries between East and West. Its strategic position and its vast resources, including petroleum and natural gas, make it a nation to be reckoned with in the modern world.