From Koblenz main train station you can reach Vallendar using the Deutsche Bahn regional trains or the number 7 or 8/8a buses (operated by evm). The bus stop in Koblenz is directly opposite the main train station. In Vallendar you get off at the “Bahnhof” (train station) stop. Both these routes take about 20 minutes each. Alternatively, you can travel southwards on a Deutsche Bahn train to Cologne, and from there take the Regional Express to Vallendar. This may be quicker than the route via Koblenz by combination of train and bus.