Iran (Persian: Irān), also known as Persia, officially the Islamic Republic of Iran (Persian: Jomhuri-ye Eslāmi-ye Irān), is a country in Western Asia. With over 81 million inhabitants, Iran is the world's 18th-most-populous country. Comprising a land area of 1,648,195 km, it is the second-largest country in the Middle East and the 17th-largest in the world. Iran is bordered to the northwest by Armenia and the Republic of Azerbaijan, to the north by the Caspian Sea, to the northeast by Turkmenistan, to the east by Afghanistan and Pakistan, to the south by the Persian Gulf and the Gulf of Oman, and to the west by Turkey and Iraq. The country's central location in Eurasia and Western Asia, and its proximity to the Strait of Hormuz, give it geostrategic importance. Tehran is the country's capital and largest city, as well as its leading economic and cultural center.