2.The National Air and Space Museum: Previously the National Air Museum founded in 1946.It has been located on the Mall since 1976. It is the most popular museum in the country, where one can see exhibits and collections of achievements in flight and space exploration. 2.The National Air and Space Museum: Previously the National Air Museum founded in 1946. It has been located on the Mall since 1976. It is the most popular museum in the country, where one can see exhibits and collections of achievements in flight and space exploration