Moscow (/ˈmɒskaʊ/ or /ˈmɒskoʊ/; Russian: Москва, tr. Moskva; IPA: [mɐˈskva] ( listen)) is the capital city and the most populous federal subject of Russia. The city is a major political, economic, cultural and scientific center in Russia and in Eastern Europe. According to Forbes 2013, Moscow has the largest number of billionaire residents in the world, has been ranked as the ninth most expensive city in the world by Mercer and is one of the world's largest urban economies, being ranked as an alpha global city according to the Globalization and World Cities Research Network and is also one of the fastest growing tourist destinations in the world according to the MasterCard Global Destination Cities Index. Moscow is the northernmost and coldest megacity and metropolis on Earth, the second most populous city in Europe after Istanbul and the 8th largest city proper in the world, as well as the largest amongst high income economies. It is home to the Ostankino Tower, the tallest free standing structure in Europe; Mercury City Tower, the tallest skyscraper in Europe and the Moscow International Business Center. It is the largest city in Russia, with a population of 12,108,257 people (2014). By its territorial expansion on 1 July 2012 southwest into the Moscow Oblast, the capital increased its area 2.5 times; from about 1,000 square kilometers (390 sq mi) up to 2,511 square kilometers (970 sq mi), and gained an additional population of 233,000 people.