A chunk of Russia is stranded between Poland and Lithuania

Kaliningrad, once the German city of Konigsberg, became Soviet territory after 1945 and is now a 15,100 sq km Russian region with no land border to the rest of Russia. Reaching it overland means crossing Lithuania or Belarus, or taking a ferry across the Baltic. It still hosts Russia's Baltic Fleet headquarters.

— Tim Marshall, Prisoners of Geography — Chapter 1: Russia, 2015
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