Dragon's teeth (fortification)Dragon's teeth (Drachenzähne) are square-pyramidal anti-tank obstacles of reinforced concrete first used during the Second World War to impede the movement of tanks and mechanised infantry. The idea was to slow down and channel tanks into killing zones where they could easily be disposed of by anti-tank weapons. They were employed extensively, particularly on the Siegfried Line. Dragon's teeth were used by several armies in the European theatre. The Germans made extensive use of them on the Siegfried Line and the Atlantic Wall.
Saint PetersburgSaint Petersburg, formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991; see below), is the second-largest city in Russia after Moscow. It is situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea. The city had a population of roughly 5.6 million residents as of 2021. Saint Petersburg is the fourth-most populous city in Europe, the most populous city on the Baltic Sea, and the world's northernmost city of more than 1 million residents.
Karelian IsthmusThe Karelian Isthmus (Karelsky peresheyek; Karjalankannas; Karelska näset) is the approximately stretch of land, situated between the Gulf of Finland and Lake Ladoga in northwestern Russia, to the north of the River Neva. Its northwestern boundary is a line from the Bay of Vyborg to the westernmost point of Lake Ladoga, Pekonlahti. If the Karelian Isthmus is defined as the entire territory of present-day Saint Petersburg and Leningrad Oblast to the north of the Neva and also a tiny part of the Republic of Karelia, the area of the isthmus is about .
Winter WarThe Winter War was a war between the Soviet Union and Finland. The war began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peace Treaty on 13 March 1940. Despite superior military strength, especially in tanks and aircraft, the Soviet Union suffered severe losses and initially made little headway. The League of Nations deemed the attack illegal and expelled the Soviet Union.
Continuation WarThe Continuation War, also known as the Second Soviet-Finnish War, was a conflict fought by Finland and Nazi Germany against the Soviet Union (USSR) from 1941 to 1944, as part of World War II. In Soviet historiography, the war was called the Finnish Front of the Great Patriotic War. Germany regarded its operations in the region as part of its overall war efforts on the Eastern Front and provided Finland with critical materiel support and military assistance, including economic aid.