If you are not travelling by vehicle The ultimate way to reach Koblenz is by educate. Trains depart often and it takes about 1.5hr from Frankfurt to Koblenz, and about 1hr from Cologne to Koblenz. An additional attraction You can't miss would be the cable car leading to the Ehrenbreitstein https://werbeagentur-koblenz65319.wikibriefing.com/2845836/a_secret_weapon_for_koblenz