Glass-Floor Cable Car to Ehrenbreitstein Fortress
Float across the Rhine in a glass-floored gondola built for the 2011 federal garden show, rising from the Deutsches Eck (German Corner) where the Rhine and Moselle meet up to Ehrenbreitstein, one of Europe's largest preserved fortresses. From the ramparts you get the definitive panorama over the confluence, the old town, and the castle-studded river bends. It's walkable from the cruise berth at Konrad-Adenauer-Ufer, making it the single must-do of any Koblenz port day.