The Kölner Seilbahn gives Cologne one of its simplest pleasures: six minutes above the Rhine, with the cathedral, Hohenzollern Bridge, Rheinpark, and the zoo side of the river all rearranged below you. It is not transport in any serious commuter sense, but it is a very good way to understand the city's east-west split and the width of the river.
The ride runs seasonally, usually from spring into autumn, between the zoo/Flora side and Rheinpark in Deutz. It pairs neatly with a walk across the Hohenzollern Bridge: cross on foot one way, float back above the water the other, and you get two completely different versions of the same skyline.