Saint Petersburg is a federal city in Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea. Formerly known as Petrograd and Leningrad, it serves as a historically strategic Baltic port and was once the capital of the Russian Empire.
The city is the second-largest city in Russia after Moscow and ranks as the fourth-most populous city in Europe. It is also the most populous city on the Baltic Sea and holds the distinction of being the world's northernmost city with a population exceeding one million residents. As of 2021, the city had a population of 5,601,911, with over 6.4 million people residing in the broader metropolitan area.
Despite its significant population and historical importance, Saint Petersburg is the smallest administrative division in Russia by area, covering 1,439 square kilometers (556 sq mi).