Kaliningrad Oblast is the westernmost federal subject of the Russian Federation, in Central and Eastern Europe. It is a semi-exclave situated on the Baltic Sea. The oblast is surrounded by two European Union and NATO members: Poland to the south and Lithuania to the north and east. The largest city and administrative centre of the province (oblast) is the city of Kaliningrad, formerly known as Königsberg. Half of the population of the oblast lives in Kaliningrad City proper. The port city of Baltiysk is Russia's only port on the Baltic Sea that remains ice-free in winter. Kaliningrad Oblast had a population of roughly 1 million in the Russian Census of 2021. The area of Kaliningrad oblast is 15,125 square kilometers.