Cologne Stadtbahn and main line railway trains, and occasional recreational boats on the Rhine. Düsseldorf is also linked by S-Bahn trains, which are operated by Deutsche Bahn. The Rhine-Ruhr S-Bahn has 5 lines which cross Cologne.The S13/S19 runs 24/7 between Cologne Hbf and Cologne/Bonn airport. There are also frequent buses covering most of the city and surrounding suburbs, and Eurolines coaches to London via Brussels. "Häfen und Güterverkehr Köln" (Ports and Goods traffic Cologne, HGK) is one of the largest operators of inland ports in Germany. Ports include Köln-Deutz, Köln-Godorf, and Köln-Niehl I and II. Cologne's international airport is Cologne/Bonn Airport
NS Documentation Centre of the City of Cologne the best pre-served prisons from the Nazi era, representing an historical asset of national and European importance. Since June, 1997, the permanent exhibition in the EL-DE building has depicted political, social and community life in "Cologne During the Nazi Era." That includes the seizure of power and the power apparatus, propaganda and the "national community," everyday life, youth culture, religion, racism, the genocide of Cologne's Jews and its Sinti and Roma, and opposition, resistance, war and society during war. In addition, temporary exhibitions depict local and national aspects of the Nazi regime. The center also mounts more than 130 events