Cologne Cologne Cologne (; , , ) is the largest city of Germany's most populous federal state of North Rhine-Westphalia, and its 1,075,935 (2016) inhabitants make it the fourth most populous city in Germany after Berlin, Hamburg, and Munich. The largest city on the Rhine, it is also the most populous city both of the Rhine-Ruhr Metropolitan Region, which is Germany's largest and one of Europe's major metropolitan areas, and of the Rhineland. Centred on the left bank of the Rhine, Cologne is about southeast of North Rhine-Westphalia's capital of Düsseldorf and northwest of Bonn. It is the largest city in
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