I'm flying with my parents from Florence to San Francisco via Dusseldorf in June. I used to live in Germany, but my parents have never visited. AirBerlin recently changed our connecting flight, so a 2 hour layover just became a 6 hour layover. I am wondering if it is feasible to land in Dusseldorf, get to Cologne Hbf to check out the Cathedral, and then back to the airport in 6 hours.
Specifically, we are arriving around 9AM on a Tuesday and our flight is around 3:30PM. I am thinking if we can get out of the airport by 10:30AM, we could get to Cologne around 11AM, 1 hour to visit the Cathedral, and then back on our way to the airport.
I know this sounds ridiculous, and for someone who lived near Cologne for a while it seems that way to me, but my parents really want to try to see Cologne Cathedral! What do you guys think? Anyone have experience getting from the Dusseldorf Airport to Dusseldorf Hpf and onwards to Cologne?