Lappeenranta Airport — Lappeenranta, Finland

Lappeenranta Airport, known by its IATA code LPP, occupies a joint civil-military site in southeastern Finland, close enough to the Russian border that its fortunes have long tracked the state of relations between the two countries. For years the airport thrived on a steady stream of Russian shoppers and short-break tourists arriving on budget carrier flights, drawn by the city's lakeside setting on Saimaa, Finland's largest lake, and by duty-free shopping unavailable at home. That cross-border traffic collapsed after airspace closures and sanctions following Russia's invasion of Ukraine, leaving the airport far quieter than in its mid-2010s peak. Lappeenranta itself is a fortified garrison town with a well-preserved old quarter overlooking the lake, and the airfield doubles as a Finnish Air Force base, giving it runway infrastructure well beyond what its modest passenger numbers would otherwise justify. General aviation, flight training, and occasional charter work keep operations ticking over today.