In May 1970,Neil Armstrong traveled to the Soviet Union to present a talk at the 13th annual conference of the International Committee on Space Research; after arriving in Leningrad from Poland, he traveled to Moscow where he met Premier Alexei Kosygin. He was the first westerner to see the supersonic Tupolev Tu-144 and was given a tour of the Yuri Gagarin Cosmonaut Training Center, which Armstrong described as "a bit Victorian in nature".
Source: Wikipedia