Sealed train

A sealed train is one that travels internationally under customs and/or immigration seal, without its contents officially entering the nations traversed between the beginning and end of the journey. The most notable use of a sealed train was the return of Vladimir Lenin to Russia from exile in Switzerland in 1917, but the practice was used a number of times throughout the 20th century to allow the migration or transport of controversial individuals or peoples. For instance, sealed trains were used for repatriation of combatants in the Spanish Civil War, Jewish emigration from Nazi Germany to the United States, and expulsion of East German refugees to West Germany.