On arrival in Mainz today, disembark the ship for a guided walking tour. Afterwards, rejoin the ship for lunch as you cruise back up the Rhine to 2000 year-old Koblenz, located at the confluence of the Rhine and the Moselle rivers. Set in one of Germany's most important wine-producing regions, Koblenz boasts an abundance of cultural monuments, historic buildings, cosy lanes and narrow alleys. Following dinner on board this evening, perhaps join your Cruise Director for a pleasant stroll through this lovely city. (B,L,D)