Saint Petersburg (Russia) (Russian Sankt Peterburg) , second largest city and largest seaport in Russia, located in the northwestern part of the country, at the head of the Gulf of Finland (an arm of the Baltic Sea). The capital of Russia for two centuries (1712-1918) , Saint Petersburg is one of the most beautiful cities in Europe, noted for its lavish palaces and grand cathedrals. It is also a major rail junction and an industrial, cultural, and scientific center. The city is located on both banks of the Neva River and on a number of river islands.Saint Petersburg has been renamed three times since its founding. Construction of the city began in 1703, ordered by Russian tsar (later emperor) Peter the Great, who named it Saint Petersburg after his patron saint. After World War I broke out in 1914, the city's Germanic name was changed to Petrograd. In 1924, upon the death of Soviet leader Vladimir Lenin, its name was changed to Leningrad. Finally, in June 1991, six months before the Union of Soviet Socialist Republics (USSR) officially dissolved and Russia emerged as an independent country, the city reverted to its original name.Saint Petersburg’s climate is one of strong contrasts. It is affected by air masses coming off the Atlantic Ocean and by polar continental air, which in winter is very dry and cold. Saint Petersburg has cold winters, with temperatures in January averaging -10° C (14° F); the summers are generally cool, with the temperature in July averaging 17° C (63° F). Although the city’s harbor is frozen for three to four months of each year, icebreakers keep it open for much of the winter season.