Kaliningrad, known as Königsberg until 1946, is the largest city and administrative centre of Kaliningrad Oblast, a Russian exclave betwe…Kaliningrad, known as Königsberg until 1946, is the largest city and administrative centre of Kaliningrad Oblast, a Russian exclave between Lithuania and Poland, 663 kilometres west of the bulk of Russia on the Pregolya River, at the head of the Vistula Lagoon, and the only ice-free Russian port on the Baltic Sea. Its population in 2020 was 489,359. Kaliningrad is the second-largest city in the Northwestern Federal District, after Saint Petersburg, the third-largest city in the Baltic region, and the seventh-largest city on the Baltic Sea.