St Petersburg (Sankt-Peterburg) is a seaport at the mouth of the River Neva, which drains into the easternmost part of the Gulf of Finland (part of the Baltic Sea). St Petersburg is in the North-Western Federal Okrug and the North-Western Economic Area. The territory, including a total of 42 islands in the Neva delta, occupies an area of 1,399 sq km (540 sq miles). At the census of October 2010 the city’s population was 4,879,566, with a population density of 3,485.4 per sq km. Of those resident in the City who stated their ethnicity at the census, 92.5% were Russian and 1.5% were Ukrainian. St Petersburg is in the time zone GMT+4.