Cologne Stadtbahn in the context of Kölner Verkehrs-Betriebe

The Cologne Bonn Region (German: Region Köln/Bonn) is a metropolitan area in North Rhine-Westphalia (NRW), Germany, covering the cities of Cologne, Bonn and Leverkusen, as well as the districts of Rheinisch-Bergischer Kreis, Oberbergischer Kreis, Rhein-Erft-Kreis and Rhein-Sieg-Kreis. The region covers an area of 3,839 km with 3.13 million inhabitants (population density 815/km). The city centres of Cologne and Bonn are 24 kilometres apart. At the outer city limits, there are only eight kilometres between Cologne-Libur and Bonn-Geislar.

The Cologne/Bonn Region was established by local governments within the Cologne Government Region in 1992, to promote common policies in regional and urban planning, traffic management, environment and investment. Among the most prominent co-operative projects are the Cologne/Bonn Airport, the Verkehrsverbund Rhein-Sieg and the former Bonn–Cologne Railway Company. Also the Stadtbahn of both cities are connected, so there are light rail trains from Cologne Stadtbahn in Bonn and the Bonn Stadtbahn in Cologne. The largest local banks, Sparkasse KölnBonn and Volksbank Köln Bonn, operate in both cities. Both cities are directly connected by the autobahn A555.

The Roman-Germanic Museum (RGM, in German: Römisch-Germanisches Museum) is an archaeological museum in Cologne, Germany. It has a large collection of Roman artifacts from the Roman settlement of Colonia Claudia Ara Agrippinensium, on which modern Cologne is built. The museum protects the original site of a Roman town villa, from which a large Dionysus mosaic remains in its original place in the basement, and the related Roman Road just outside. In this respect the museum is an archaeological site.

The museum also has the task of preserving the Roman cultural heritage of Cologne, and therefore houses an extensive collection of Roman glass from funerals and burials and also exercises archaeological supervision over the construction of the Cologne underground.

The Bonn Stadtbahn (German: Stadtbahn Bonn) is a Stadtbahn system in Bonn and the surrounding Rhein-Sieg area, that also includes the Bonn Straßenbahn. Although with six actual Stadtbahn lines (as well as three tram lines) the network is relatively small, two of Bonn's Stadtbahn lines connect to the much larger Cologne Stadtbahn (and are numbered according to that system, not Bonn's).

The Stadtbahn network comprises 95.84 kilometres (59.55 mi) of route. There are 64 stations and stops in the city of Bonn proper, and another 17 in the Rhein-Sieg-Kreis. Additionally, 8.72 kilometres (5.42 mi) of the Stadtbahn is located underground, as are 12 of the Stadtbahn stations.

Green track (also grassed track or lawn track) is a type of railway track in which the track bed and surrounding area are planted with grass turf or other vegetation as ground cover. It is a popular way of making railways more visually appealing, particularly for trams and light rail, and providing additional urban green space. Aside from the visual improvement, the vegetation provides a number of positive effects, such as noise reduction, less air pollution, rainwater runoff mitigation, and reduced urban heat island effect.