 The Olympic Stadium and Helsinki-Malmi Airport are also catalogued by the Finnish National Board of Antiquities as cultural-historical environments of national significance.Helsinki's neoclassical buildings were often used as a backdrop for scenes set to take place in the Soviet Union in many Cold War era Hollywood movies, when filming in the USSR was not possible.Some of them include "The Kremlin Letter" (1970), "Reds" (1981), and "Gorky Park" (1983).