Moscow is the capital of Russia and the countrys principal political, economic, financial, educational, and transportation center, located on the Moskva River in the Central Federal District, in the European part of Russia. The traditional standard pronunciation of the name in English, derived from its German name "Moskau", is "Moskow" ("kow" rhyming with "cow"), but in recent years the pronunciation "Moskoh", of uncertain origin, has been widely used. The city's population of 10.4 million permanent inhabitants within the city boundaries constitutes about 7% of the total Russian population. Likewise, it is the most populous city in Europe. Historically, its position was central in the Russian homeland. It was the capital of the former Soviet Union and Muscovite Russia, the pre-Imperial Russian state. It is the site of the famous Kremlin, which now serves as the ceremonial residence of the President.
Moscow's architecture and performing arts culture are world-renowned. Moscow is also well known as the site of Saint Basil's Cathedral, with its elegant onion domes, as well as the Cathedral of Christ the Savior. The Patriarch of Moscow, whose residence is the Danilov Monastery, serves as the head of the Russian Orthodox Church. Moscow also remains a major economic center and is home to a large number of billionaires; it is perennially considered one of the most expensive cities for expatriate employees in the world.It is home to many scientific and educational institutions, as well as numerous sport facilities. It possesses a complex transport system that includes the world's busiest metro system, which is famous for its architecture. Moscow also became the host of the 1980 Summer Olympics.