Cologne headquarters and workshops in Cologne. Other large companies based in Cologne include the REWE Group, TÜV Rheinland, Deutz AG and a number of Kölsch breweries. Cologne has the country's highest density of pubs per capita. The largest three Kölsch breweries are Reissdorf, Gaffel, and Früh. Historically, Cologne has always been an important trade city, with land, air, and sea connections. The city has five Rhine ports, the second largest inland port in Germany and one of the largest in Europe. Cologne-Bonn Airport is the second largest freight terminal in Germany. Today, the Cologne trade fair ("Koelnmesse") ranks as a major
Historical Archive of the City of Cologne the 1897 building has been used as a private library by Gerling, a large insurance company. In 1971, a six-story archive building by architect Fritz Haferkamp was built on Severinstraße in the southern part of Cologne's city center. An underlying principle of the design was to protect archival records from fluctuations in weather and climate while creating a balanced room climate. In a move away from the contemporary popularity of electromechanical air conditioning, Haferkamp preferred a structural-physical, self-regulating solution that needed only little additional climate technology. As the "Cologne Model", the building became a model for many later archive buildings