Iran, officially the Islamic Republic of Iran, and also called Persia, is a country in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmenistan to the north, by Afghanistan and Pakistan to the east, and by the Gulf of Oman and the Persian Gulf to the south. It covers an area of 1.64 million square kilometres (0.63 million square miles), making it the 17th-largest country. Iran has a population of 86 million, making it the 17th-most populous country in the world, and the second-largest in the Middle East. Its largest cities, in descending order, are the capital Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz. Iran is a regional and middle power, with a geopolitically strategic location in the Asian continent. It is a founding member of the United Nations, the ECO, the OIC, and the OPEC. It has large reserves of fossil fuels—including the second-largest natural gas supply and the third-largest proven oil reserves. The country's rich cultural legacy is reflected in part by its 26 UNESCO World Heritage Sites. Historically a multi-ethnic country, Iran remains a pluralistic society comprising numerous ethnic, linguistic, and religious groups, with the largest of these being Persians, Azeris, Kurds, Mazandaranis, and Lurs. (Source: Wikipedia.org, CC BY-SA)