By train: The central train station is immediately below the cathedral - a very impressing view when you enter the city by train. From the "Hauptbahnhof" you can reach many sights, pubs and hotels by walking.
By air: The international airport Köln-Bonn is situated half way between the two cities. By taking the airport bus Nr. 170 you will reach the Cologne central station. The bus leaves at 20-minute intervals. A taxi ride from the airport to the city centre takes about 20 minutes and will cost around 40 DM.
By car: Cologne is surrounded by concentric Rings, thus orientation is not really difficult. The outest is the "Autobahnring". From here the main arterials radiate inwards the city. If you just follow the centre signs, you will reach the Dom as well as the central station, where you can park rather easily (underground parking) but it will cost you more than in the outer areas.