I always love seeing a city from above. The Rheinturm offers impressive views of Düsseldorf and its surroundings. Really worth the trip up and down the very fast elevator. You can have a drink at the bar or dine in the revolving restaurant if you like.
Theinturm (Rhine Tower) Düsseldorf
Visited December 2015. You can find my review about Rhine Tower (Rheinturm) also on TripAdvisor.