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 so-called White Book ("Weißes Buch"), a book of copies of charters and privileges. By 1370 the archives were located in the "Haus zur Stessen". In medieval Cologne, valuable goods and important trade documents were frequently stored in vaulted warehouses specially built in backyards. This method of storage was used by both business owners and the municipal administration. Documents included grants of privileges, contracts, records of lawsuits, maps, seals and documents from the estates of important persons. As the city and its national and international trade thrived and prospered, the municipal administration began to plan further storage to house the growing