History of Cologne was considered a substitute for the German University of Strasbourg, which became part of France along with the rest of Alsace. Cologne prospered during the Weimar Republic and progress was made especially in governance, city planning and social affairs. Social housing projects were considered exemplary and were copied by other German cities. As Cologne competed to host the Olympics, a modern sports stadium was erected at Müngersdorf. Beginning of the 1920s civil aviation was permitted once more, and Cologne Butzweilerhof Airport soon became a hub for national and international air traffic, second in Germany only to Berlin Tempelhof Airport. At
Cologne Cologne's economy prospered for two main reasons. The first was the growth in the number of media companies, both in the private and public sectors; they are especially catered for in the newly developed Media Park, which creates a strongly visual focal point in Cologne city centre and includes the "KölnTurm", one of Cologne's most prominent high-rise buildings. The second was the permanent improvement of the diverse traffic infrastructure, which made Cologne one of the most easily accessible metropolitan areas in Central Europe. Due to the economic success of the Cologne Trade Fair, the city arranged a large extension to